Chromosomal inversion and translocation between 3q21 and 3q26 [inv (3)(q21.3q26.2) and t(3;3)(q21.3;q26.2), respectively] give rise to acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS), which have poor prognoses. The chromosomal rearrangements reposition a GATA2 distal hematopoietic enhancer from the original 3q21 locus to the EVI1 (also known as MECOM) locus on 3q26. Therefore, the GATA2 enhancer from one of two GATA2 alleles drives EVI1 gene expression in hematopoietic stem and progenitor cells, which promotes the accumulation of abnormal progenitors and induces leukemogenesis. On the other hand, one allele of the GATA2 gene loses its enhancer, which results in reduced GATA2 expression. The GATA2 gene encodes a transcription factor critical for the generation and maintenance of hematopoietic stem and progenitor cells. GATA2 haploinsufficiency has been known to cause immunodeficiency and myeloid leukemia. Notably, reduced GATA2 expression suppresses the differentiation but promotes the proliferation of EVI1-expressing leukemic cells, which accelerates EVI1-driven leukemogenesis. A series of studies have shown that the GATA2 enhancer repositioning caused by the chromosomal rearrangements between 3q21 and 3q26 provokes misexpression of both the EVI1 and GATA2 genes and that these two effects coordinately elicit high-risk leukemia.

Blood is an example of a highly regenerative tissue and its regeneration depends on the presence of stem cells residing in the bone marrow in humans. A better understanding of how these stem cells are programmed would benefit their use in clinical practice and shed light on the mechanisms by which the unique properties of stem cells are established. Our approach is to delineate the gene regulatory networks (GRNs) that specify these cells during their development in the embryo, and we use the amphibian experimental model because a wealth of evidence shows that the mechanisms used are conserved in mammals including humans. Blood stem cells are made during the intraembryonic wave of hematopoiesis during embryonic development where they emerge from endothelial precursors in the floor of the dorsal aorta (DA). These cells are derived from lateral plate mesoderm and so we have focused on the subset of cells in the lateral plate mesoderm fated to become blood and endothelium known as definitive hemangioblasts. We have found that their programming results from the activities of vascular endothelial growth factor A (VEGFA) and bone morphogenetic protein (BMP) signaling and the inhibition by miRNA of transforming growth factor beta signaling. VEGFA is first generated in the somites adjacent to the lateral plate mesoderm, and one of the responses of the lateral plate mesoderm is to activate endogenous VEGFA expression. BMP has multiple inputs into the programming of these cells via the activation of the transcription factor (TF), Gata2, and of the VEGFA receptor. These actions culminate in the expression of the leukemia-associated TF, Scl/Tal1, which is essential for blood fate specification. The activity of VEGFA in driving endothelial development resides in the small isoform, but the medium and large isoforms are required to initiate the blood stem cell program in the floor of the DA. The expression of the small isoform is dependent on the blood TF with leukemia connections, Tel1/Etv6, whereas the larger isoforms depend on another transcription-associated factor with leukemia connections, Eto2, raising the possibility that the regulation of VEGFA expression may be the mode of action of these leukemic factors. The action of Tel1/Etv6 in directly activating VEGFA expression in the somites was unexpected because this TF had only been reported to repress transcription. Using chromatin immunoprecipitation technology, we were able to show that Tel1/Etv6 does indeed work by repressing the expression of a VEGFA repressor, FoxC3, but it also acts directly to activate VEGFA expression, working together with Klf4. Finally, we have also looked at the mesodermal population that gives rise to the earlier waves of hematopoiesis, which do not generate a stem cell. We find significant differences including differential use of TFs of the E-Twenty-Six (ETS) family. In conclusion, we have elucidated the GRN responsible for preparing the lateral mesoderm for blood stem cell production.

Recent research reveals novel insights into the pathogenesis of childhood myelodysplastic syndromes (MDS) in addition to that of juvenile myelomonocytic leukemia (JMML). In pediatric MDS, the genetic characteristics of which have been barely elucidated previously, germline mutations, particularly those in GATA2, SAMD9, and SAML9L, have been frequently identified, indicating the importance of germline predisposition in childhood MDS compared with adult MDS. In JMML, in addition to the known Ras-pathway mutations, novel secondary mutations and causative fusion genes have been reported. This review aims to summarize the recent progress in the research of the pathogenesis of childhood MDS and JMML.

Lymphatic vasculature is an integral part of the cardiovascular system where it maintains interstitial fluid balance. Additionally, lymphatic vasculature regulates lipid assimilation and inflammatory response. Lymphatic vasculature is composed of lymphatic capillaries, collecting lymphatic vessels and valves that function in synergy to absorb and transport fluid against gravitational and pressure gradients. Defects in lymphatic vessels or valves leads to fluid accumulation in tissues (lymphedema), chylous ascites, chylothorax, metabolic disorders and inflammation. The past three decades of research has identified numerous molecules that are necessary for the stepwise development of lymphatic vasculature. However, approaches to treat lymphatic disorders are still limited to massages and compression bandages. Hence, better understanding of the mechanisms that regulate lymphatic vascular development and function is urgently needed to develop efficient therapies. Recent research has linked mechanical signals such as shear stress and matrix stiffness with biochemical pathways that regulate lymphatic vessel growth, patterning and maturation and valve formation. The goal of this review article is to highlight these innovative developments and speculate on unanswered questions.

Keywords: FOXC2; GATA2; Lymphatic endothelial cells; Lymphatic vascular development; Mechanotransduction; PROX1; Shear stress; Valve; Wnt; YAP/TAZ.

Objective: To describe fertility characteristics, outcomes of oocyte cryopreservation cycles, and safety of ovarian stimulation in patients with GATA binding protein 2 (GATA2) deficiency, dedicator of cytokinesis 8 (DOCK8) deficiency, and sickle cell disease (SCD) preparing for hematopoetic stem cell transplantation (HSCT).

Design: Retrospective case series.

Setting: The National Institutes of Health.

Patients: Female patients with GATA2 deficiency, DOCK8 deficiency, and SCD aged between 13 and 38 years.

Interventions: None.

Main outcome measures: Demographic and ovarian reserve parameters, stimulation outcomes, and adverse event occurrences were collected through chart review. Descriptive statistics were used to identify trends within disease subcategories.

Results: Twenty-one women with GATA2 deficiency, DOCK8 deficiency, and SCD underwent fertility preservation prior to HSCT. Patients with DOCK8 deficiency had the lowest mean age (16.5 years old) and antimüllerian hormone (0.85 ng/mL). Patients with GATA2 deficiency had the highest antral follicle count and antimüllerian hormone (25.77 and 5.07 ng/mL, respectively). Baseline follicle-stimulating hormone, luteinizing hormone, and estradiol were comparable between the cohorts. The duration of stimulation was similar (10.43 to 11.25 days) across all groups. Comparable peak estradiol levels were achieved across the cohorts. Patients with SCD had the highest mature (MII) oocyte yield (10.71). Three patients experienced complications related to stimulation: pain crisis in a patient with SCD, pulmonary embolism, and zero oocytes cryopreserved in a patient with GATA2 deficiency.

Conclusions: This study offers insight into controlled ovarian stimulation in patients with these conditions prior to HSCT. Oocyte cryopreservation can be performed successfully, although adverse events must be considered. Following the outcomes of gamete use in this cohort will serve to further our knowledge of the true reproductive potential of this population.

Keywords: DOCK8 deficiency; Fertility preservation; GATA2 deficiency; hematopoetic stem cell transplantation; sickle cell disease.

GATA2 is a transcription factor with key roles in hematopoiesis. Germline GATA2 gene variants have been associated with several inherited and acquired hematologic disorders, including myelodysplastic syndromes. Among the spectrum of GATA2 deficiency-associated manifestations thrombosis has been reported in 25% of patients, but the mechanisms are unknown. GATA2 was shown to be involved in endothelial nitric oxide synthase (eNOS) regulation and vascular development. We assessed eNOS expression and angiogenesis in patients with GATA2-deficiency. Platelets and blood outgrowth endothelial cells (BOEC) from GATA2-variant carriers showed impaired NO-production and reduction of eNOS mRNA and protein expression and of eNOS activity. GATA2 binding to the eNOS gene was impaired in BOEC from GATA2-deficiency patients, differently from control BOEC. GATA2-deficiency BOEC showed also defective angiogenesis, which was completely restored by treatment with the NO-donor S-nitroso-N-acetylpenicillamine (SNAP). Atorvastatin, but not resveratrol, largely restored eNOS expression, NO biosynthesis and neoangiogenesis in GATA2-deficient BOEC by a mechanism involving increased expression of the eNOS transcription factor AP-1/c-JUN, replacing GATA2 when the latter is inactive. Our results unravel a possible thrombogenic mechanism of GATA2 mutations, definitely establish the regulation of eNOS by GATA2 in endothelial cells and show that endothelial angiogenesis is strictly dependent on the eNOS/NO axis. Given the ability of atorvastatin to restore NO production and angiogenesis by GATA2-deficient endothelial cells, the preventive effect of atorvastatin on thrombotic events and possibly on other clinical manifestations of the syndrome related to deranged angiogenesis should be explored in patients with GATA2-deficiency in an ad hoc designed clinical trial.

Pathogenic germ-line variants in GATA2 (GATA2-deficiency) can cause childhood myelodysplastic syndrome (MDS) and acute myeloid leukaemia (AML), and can be associated with distinct clinical syndromic features. However, penetrance and genotype-phenotype correlations are incompletely understood. Here we report on the clinically diverse features of three siblings affected by GATA2c.1021_1031del over an 18-year period, all initially presenting in childhood and adolescence with MDS and AML with monosomy 7 (-7), and one also with trisomy 8 (+8). The siblings inherited a GATA2c.1021_1031del from their father who remains asymptomatic in his sixth decade. The two younger sisters are well after unrelated haematopoietic stem cell transplantation (HSCT), while the first boy died of severe chronic lung disease after sibling HSCT from his youngest sister, who subsequently also developed GATA2-deficiency associated MDS. This family illustrates high penetrance with variable genotype/phenotype correlation within one generation with GATA2-deficiency. We surmise that the lung disease post sibling HSCT was also caused by the GATA2-deficiency. The experience with this family underlines the necessity for GATA2 analysis in all apparently sporadic childhood and teenage MDS and AML with -7 also in the absence of a family history or other clinical features, and rigorous genetic testing in siblings. Moreover, our findings support the arguments for pre-emptive HSCT in variant-carrying siblings.

Our understanding of cell fate decisions in hematopoietic stem cells is incomplete. Here, we show that the transcription factor Helios is highly expressed in murine hematopoietic stem and progenitor cells (HSPCs), where it is required to suppress the separation of the platelet/megakaryocyte lineage from the HSPC pool. Helios acts mainly in quiescent cells, where it directly represses the megakaryocyte gene expression program in cells as early as the stem cell stage. Helios binding promotes chromatin compaction, notably at the regulatory regions of platelet-specific genes recognized by the Gata2 and Runx1 transcriptional activators, implicated in megakaryocyte priming. Helios null HSPCs are biased toward the megakaryocyte lineage at the expense of the lymphoid and partially resemble cells of aging animals. We propose that Helios acts as a guardian of HSPC pluripotency by continuously repressing the megakaryocyte fate, which in turn allows downstream lymphoid priming to take place. These results highlight the importance of negative and positive priming events in lineage commitment.

NFATc1, which is ubiquitous in many cell types, is the master regulator of osteoclastogenesis. However, the molecular mechanisms by which NFATc1 drives its transcriptional program to produce osteoclasts from macrophages (M) remains poorly understood. We performed quantitative PCR (QPCR) arrays and bioinformatic analyses to discover new direct and indirect NFATc1 targets. The results revealed that NFATc1 significantly modified the expression of 55 genes in untransfected cells and 31 genes after NFATc1-knockdown (≥2). Among them, we focused on 19 common genes that showed changes in the PCR arrays between the two groups of cells. Gene Ontology (GO) demonstrated that genes related to cell differentiation and the development process were significantly (p > 0.05) affected by NFATc1-knockdown. Among all the genes analyzed, we focused on GATA2, which was up-regulated in NFATc1-knockdown cells, while its expression was reduced after NFATc1 rescue. Thus, we suggest GATA2 as a new target of NFATc1. Ingenuity Pathway Analysis (IPA) identified up-regulated GATA2 and the STAT family members as principal nodes involved in cell differentiation. Mechanistically, we demonstrated that STAT6 was activated in parallel with GATA2 in NFATc1-knockdown cells. We suggest an alternative pathway for macrophage differentiation in the absence of NFATc1 due to the GATA2 transcription factor.

Endometrial cancer (EC) is one of the most common malignancies in the female genital system, characterized by high mortality and recurrence rates. This study attempted to screen key genes and potential prognostic biomarkers for EC using bioinformatics analysis. Twenty-seven normal endometrial tissues and 135 EC samples were collected from four Gene Expression Omnibus (GEO) databases, then we identified the differentially expressed genes (DEGs) and conducted downstream analyses. Moreover, we screened hub genes by constructing a protein-protein interaction (PPI) network. Finally, we assessed the prognostic values and molecular mechanism of the potential prognostic genes using the Kaplan-Meier curve and Gene Set Enrichment Analysis (GSEA). As a result, 28 upregulated and 94 downregulated genes were determined after gene integration of these four GEO data sets. Gene Ontology analysis indicated that DEGs were mainly involved in transcriptional regulation and cell proliferation. The Kyoto Encyclopedia of Gene and Genome pathway analysis primarily related to transcriptional misregulation and apoptosis. Moreover, the PPI analysis revealed 10 hub genes (JUN, UBE2I, GATA2, WT1, PIAS1, FOXL2, RUNXI, EZR, TCF4, and NR2F2) with a high degree of connectivity, among them, the expression tendency of nine genes except UBE2I were consistent with messenger RNA level from The Cancer Genome Atlas data. Furthermore, only FOXL2, TCF4, and NR2F2 were significantly correlated with prognosis of EC patients, and their low expression associated biological pathways were enriched in the cell cycle and fatty acid metabolism. In conclusion, this study identified three key genes as biomarkers and potential therapeutic targets of EC on the basis of integrated bioinformatics analysis. The findings will improve our comprehension of the molecular mechanisms underlying the pathogenesis and prognosis of EC.

Keywords: GEO; GSEA; TCGA; bioinformatics; biomarker; endometrial cancer.

Herein, we report the case of a 12-year-old female who noted the recent onset of an oval, circumscribed, 10-cm papillomatous plaque affecting the thigh and vulva that showed histologic signs of lymphedema without evidence of secondary lymphedema. The sequencing of genes associated with a delayed onset of lymphedema or epidermal nevi (EN) - GATA2 and GJC2, and HRAS and KRAS, respectively - showed wild-type alleles. Polymerase chain reaction for human papillomavirus (HPV) DNA demonstrated infections with 15 HPV genotypes. Evidence of productive HPV infection, HPV capsid expression, and cytopathic changes was detected. At the 6-month follow-up, no evidence of recurrence was found after complete excision. The analysis of a consecutive series of 91 EN excision specimens revealed that 76% exhibited histologic evidence of lymphostasis. Notably, multiple acrochordon-like EN, which most closely resembled this case, showed similar signs of localized lymphedema. The late onset and evidence of lymphedema favors the diagnosis of congenital unisegmental lymphedema. However, the clinical findings and epidermal changes point to the diagnosis of EN. Moreover, localized verrucosis also accurately describes this patient's cutaneous findings. Based on the above evidence, we postulate that an abnormal development of lymphatics may play a primary role in the pathogenesis of some types of EN and facilitate productive HPV infection.

Dendritic Cells (DCs), derived from haematopoietic stem cells, are critical to the dynamic and balanced functioning of the intact immune system and are of great interest as vehicles of immunotherapy. Genetically modified mouse models have proved powerful tools to map DC development and function in vivo but human studies have previously relied heavily on in vitro systems. Human dendritic cell immunodeficiency, resulting from single gene mutations, offers new opportunities to dissect the role of human DCs in vivo, determine the genetic requirements for their development and map their haematopoietic differentiation pathways. This review will summarise the clinical phenotypes of mutations in GATA2, IRF8 and IKZF1 genes which result in global or subset specific dendritic cell deficiencies, discuss the functional consequences of these cytopenias and how these syndromes have informed our knowledge of DC differentiation and human haematopoiesis.

GATA2 is a transcription factor that is involved in the lympho-hematopoiesis. Mutations of GATA2 cause MonoMAC syndrome (monocytopenia and mycobacterial infections)/DCML deficiency (dendritic cell, monocyte, B and natural killer (NK) lymphoid deficiency), Emberger syndrome (lymphoedema with MDS), and MDS/AML. In this review, we explain the new function of GATA2, and describe the clinical phenotypes, laboratory findings, pathology, genetic anomalies and etiology.

The serum concentration of thyrotropin (thyroid stimulating hormone, TSH) is drastically reduced by small increase in the levels of thyroid hormones (T3 and its prohormone, T4); however, the mechanism underlying this relationship is unknown. TSH consists of the chorionic gonadotropin α (CGA) and the β chain (TSHβ). The expression of both peptides is induced by the transcription factor GATA2, a determinant of the thyrotroph and gonadotroph differentiation in the pituitary. We previously reported that the liganded T3 receptor (TR) inhibits transactivation activity of GATA2 via a tethering mechanism and proposed that this mechanism, but not binding of TR with a negative T3-responsive element, is the basis for the T3-dependent inhibition of the TSHβ and CGA genes. Multiple GATA-responsive elements (GATA-REs) also exist within the GATA2 gene itself and mediate the positive feedback autoregulation of this gene. To elucidate the effect of T3 on this non-linear regulation, we fused the GATA-REs at -3.9 kb or +9.5 kb of the GATA2 gene with the chloramphenicol acetyltransferase reporter gene harbored in its 1S-promoter. These constructs were co-transfected with the expression plasmids for GATA2 and the pituitary specific TR, TRβ2, into kidney-derived CV1 cells. We found that liganded TRβ2 represses the GATA2-induced transactivation of these reporter genes. Multi-dimensional input function theory revealed that liganded TRβ2 functions as a classical transcriptional repressor. Then, we investigated the effect of T3 on the endogenous expression of GATA2 protein and mRNA in the gonadotroph-derived LβT2 cells. In this cell line, T3 reduced GATA2 protein independently of the ubiquitin proteasome system. GATA2 mRNA was drastically suppressed by T3, the concentration of which corresponds to moderate hypothyroidism and euthyroidism. These results suggest that liganded TRβ2 inhibits the positive feedback autoregulation of the GATA2 gene; moreover this mechanism plays an important role in the potent reduction of TSH production by T3.

IL-13 plays a critical role in mediating many biological processes responsible for allergic inflammation. Mast cells express Il13 mRNA and produce IL-13 protein in response to antigenic stimulation. Enhancers are essential in promoting gene transcription and are thought to activate transcription by delivering essential accessory cofactors to the promoter to potentiate gene transcription. However, enhancers mediating Il13 have not been identified. Furthermore, which Il13 enhancers detect signals triggered by antigenic stimulation have not yet been defined. In this study, we identified potential mouse Il13 enhancers using histone modification monomethylation at lysine residue 4 on histone 3 (H3K4me1) chromatin immunoprecipitation sequencing and acetylation at lysine residue 27 on histone 3 (H3K27ac) chromatin immunoprecipitation sequencing. We used Omni-assay for transposase-accessible chromatin sequencing to determine which accessible regions within the potential Il13 enhancers that responded to IgE receptor crosslinking. We also demonstrated that the transcription factor cluster consisting of the NFATC2, STAT5, GATA2, AP1, and RUNX1 binding sites at the proximal Il13 enhancer and the transcription factor cluster consisting of the EGR2 binding site at the distal Il13 E+6.5 enhancer are critical in sensing the signals triggered by antigenic stimulation. Those enhancers, which are responsive to antigenic stimulation and are constitutively active, cooperate to generate greater transcriptional outputs. Our study reveals a novel mechanism underlying how antigenic stimulation induces robust Il13 mRNA expression in mouse mast cells.

Recently, we documented a hematopoietic NKL-code mapping physiological expression patterns of NKL homeobox genes in human myelopoiesis including monocytes and their derived dendritic cells (DCs). Here, we enlarge this map to include normal NKL homeobox gene expressions in progenitor-derived DCs. Analysis of public gene expression profiling and RNA-seq datasets containing plasmacytoid and conventional dendritic cells (pDC and cDC) demonstrated HHEX activity in both entities while cDCs additionally expressed VENTX. The consequent aim of our study was to examine regulation and function of VENTX in DCs. We compared profiling data of VENTX-positive cDC and monocytes with VENTX-negative pDC and common myeloid progenitor entities and revealed several differentially expressed genes encoding transcription factors and pathway components, representing potential VENTX regulators. Screening of RNA-seq data for 100 leukemia/lymphoma cell lines identified prominent VENTX expression in an acute myelomonocytic leukemia cell line, MUTZ-3 containing inv(3)(q21q26) and t(12;22)(p13;q11) and representing a model for DC differentiation studies. Furthermore, extended gene analyses indicated that MUTZ-3 is associated with the subtype cDC2. In addition to analysis of public chromatin immune-precipitation data, subsequent knockdown experiments and modulations of signaling pathways in MUTZ-3 and control cell lines confirmed identified candidate transcription factors CEBPB, ETV6, EVI1, GATA2, IRF2, MN1, SPIB, and SPI1 and the CSF-, NOTCH-, and TNFa-pathways as VENTX regulators. Live-cell imaging analyses of MUTZ-3 cells treated for VENTX knockdown excluded impacts on apoptosis or induced alteration of differentiation-associated cell morphology. In contrast, target gene analysis performed by expression profiling of knockdown-treated MUTZ-3 cells revealed VENTX-mediated activation of several cDC-specific genes including CSFR1, EGR2, and MIR10A and inhibition of pDC-specific genes like RUNX2. Taken together, we added NKL homeobox gene activities for progenitor-derived DCs to the NKL-code, showing that VENTX is expressed in cDCs but not in pDCs and forms part of a cDC-specific gene regulatory network operating in DC differentiation and function.

Keywords: AML; NKL-code; T-ALL; cell lines; homeobox.

Normal karyotype acute myeloid leukemia (NK-AML) constitutes 20-25% of pediatric AML and detailed molecular analysis is essential to unravel the genetic background of this group. Using publicly available sequencing data from the TARGET-AML initiative, we investigated the mutational landscape of NK-AML in comparison with abnormal karyotype AML (AK-AML). In 164 (97.6%) of 168 independent NK-AML samples, at least one somatic protein-coding mutation was identified using whole-genome or targeted capture sequencing. We identified a unique mutational landscape of NK-AML characterized by a higher prevalence of mutated CEBPA, FLT3, GATA2, NPM1, PTPN11, TET2, and WT1 and a lower prevalence of mutated KIT, KRAS, and NRAS compared with AK-AML. Mutated CEBPA often co-occurred with mutated GATA2, whereas mutated FLT3 co-occurred with mutated WT1 and NPM1. In multivariate regression analysis, we identified younger age, WBC count ≥50 × 10⁹/L, FLT3-internal tandem duplications, and mutated WT1 as independent predictors of adverse prognosis and mutated NPM1 and GATA2 as independent predictors of favorable prognosis in NK-AML. In conclusion, NK-AML in children is characterized by a unique mutational landscape which impacts the disease outcome.

Keywords: cancer genetics; cytogenetically normal; cytogenetics; diagnosis; molecular genetics; mutational landscape; normal karyotype; pediatric acute myeloid leukemia; prognosis; survival.

GATA2, a key transcription factor in hematopoiesis, is frequently mutated in hematopoietic malignancies. How the GATA2 mutants contribute to hematopoiesis and malignant transformation remains largely unexplored. Here, we report that Gata2-L359V mutation impeded hematopoietic differentiation in murine embryonic and adult hematopoiesis and blocked murine chronic myeloid leukemia (CML) cell differentiation. We established a Gata2-L359V knockin mouse model in which the homozygous Gata2-L359V mutation caused major defects in primitive erythropoiesis with an accumulation of erythroid precursors and severe anemia, leading to embryonic lethality around E11.5. During adult life, the Gata2-L359V heterozygous mice exhibited a notable decrease in bone marrow (BM) recovery under stress induction with cytotoxic drug 5-fluorouracil. Using RNA sequencing, it was revealed that homozygous Gata2-L359V suppressed genes related to embryonic hematopoiesis in yolk sac, while heterozygous Gata2-L359V dysregulated genes related to cell cycle and proliferation in BM Lin^-Sca1⁺c-kit⁺ cells. Furthermore, through chromatin immunoprecipitation sequencing and transactivation experiments, we found that this mutation enhanced the DNA-binding capacity and transcriptional activities of Gata2, which was likely associated with the altered expression of some essential genes during embryonic and adult hematopoiesis. In mice model harboring BCR/ABL, single-cell RNA-sequencing demonstrated that Gata2-L359V induced additional gene expression profile abnormalities and partially affected cell differentiation at the early stage of myelomonocytic lineage, evidenced by the increase of granulocyte-monocyte progenitors and monocytosis. Taken together, our study unveiled that Gata2-L359V mutation induces defective hematopoietic development and blocks the differentiation of CML cells.