We aimed to evaluate the determinants of survival in myelofibrosis patients undergoing allogeneic hematopoietic cell transplantation (allo-HCT) and to describe factors predicting the main post-HCT complications. This retrospective study by the European Society for Blood and Marrow Transplantation included 2916 myelofibrosis patients who underwent first allo-HCT from an HLA-identical sibling or unrelated donor between 2000 and 2016. After a median follow-up of 4.7 years from transplant, projected median survival of the series was 5.3 years. Factors independently associated with increased mortality were age ≥ 60 years and Karnofsky Performance Status <90% at transplant, and occurrence of graft failure, grades III-IV acute graft-vs.-host disease (aGVHD), and disease progression/relapse during follow-up. The opposing effects of chronic graft-vs.-host disease (GVHD) on non-relapse mortality and relapse incidence resulted in a neutral influence on survival. Graft failure increased in unrelated donor recipients and decreased with myeloablative conditioning (MAC) and negative donor/recipient cytomegalovirus serostatus. Risk of grades III-IV aGVHD was higher with unrelated donors and decreased with MAC. Relapse incidence tended to be higher in patients with intermediate-2/high-risk DIPSS categories and to decrease in CALR-mutated patients. Acute and chronic GVHD reduced the subsequent risk of relapse. This information has potential implications for patient counseling and clinical decision-making.

Mouse cancers lacking the expression of annexin A1 (ANXA1) fail to respond to immunogenic chemotherapies. This has been initially explained by the requirement of extracellular ANXA1 (which is released from dying cancer cells) to engage formyl peptide receptor-1 (FPR1) on dendritic cells (DC) for the establishment of corpse/DC synapses. Here, we show that ANXA1-deficent cancer cells exhibit a defect in the exposure of calreticulin (CALR), which is an important "eat-me" signal, facilitating the phagocytic uptake of dead-cell antigens by DC. Of note, intratumoral injection of recombinant CALR protein was able to restore the therapeutic response of ANXA1-deficient cancers to anthracycline-based chemotherapy. Carcinomas developing in patients tend to downregulate ANXA1 expression as compared to their normal tissues of origin. ANXA1-low breast, colorectal, lung and kidney cancers are scarcely infiltrated by DC and cytotoxic T lymphocytes, supporting the idea that ANXA1 deficiency facilitates immune escape. We propose that such ANXA1-low cancers might be particularly suitable to local immunotherapy with CALR protein.

Keywords: Calreticulin; chemotherapy; immunogenic cell death; immunotherapy; prognostic markers; tumor immune infiltrate.

Philadelphia-negative chronic myeloproliferative neoplasms (MPNs) have recently been revealed to be related to chronic inflammation, oxidative stress, and the accumulation of reactive oxygen species. It has been proposed that MPNs represent a human inflammation model for tumor advancement, in which long-lasting inflammation serves as the driving element from early tumor stage (over polycythemia vera) to the later myelofibrotic cancer stage. It has been theorized that the starting event for acquired stem cell alteration may occur after a chronic inflammation stimulus with consequent myelopoietic drive, producing a genetic stem cell insult. When this occurs, the clone itself constantly produces inflammatory components in the bone marrow; these elements further cause clonal expansion. In BCR-ABL1-negative MPNs, the driver mutations include JAK 2, MPL, and CALR. Transcriptomic studies of hematopoietic stem cells from subjects with driver mutations have demonstrated the upregulation of inflammation-related genes capable of provoking the development of an inflammatory state. The possibility of acting on the inflammatory state as a therapeutic approach in MPNs appears promising, in which an intervention operating on the pathways that control the synthesis of cytokines and oxidative stress could be effective in reducing the possibility of leukemic progression and onset of complications.

Keywords: ROS; driver mutation; essential thrombocythemia; inflammation; myelofibrosis; myeloproliferative neoplasms; oxidative stress; polycythemia vera; thrombotic complication.

Cholecystokinin (CCK) is a peptide hormone released from the I-cells of the upper small intestine. CCK evokes a variety of physiological responses, such as stimulation of pancreatic secretion, reduction of food intake and inhibition of gastric emptying. Previously, we reported that CCK activates enteric neurons in the rat. However the specific subpopulations of enteric neurons activated by CCK have not been identified. In the work reported here, we utilized immunohistochemical detection of nuclear Fos, a marker for neuronal activation, and selected phenotypic markers to identify some of the neuronal subpopulations activated by CCK. The phenotypic markers that we examined were: nitric oxide synthase (NOS), neurokinin-1 receptor (NK-1R), calbindin (Cal), Calretinin (Calr), and neurofilament-M (NF-M). We found that in the myenteric plexus of the rat duodenum and jejunum, CCK activated NOS immunoreactive neurons. In the submucosal plexus of duodenum and jejunum, CCK activated Cal, Calr and NF-M immunoreactive neurons. CCK failed to activate NK-1R immunoreactive neurons in either plexus. Our results indicate that CCK activates distinct enteric neurons in the rat upper small intestine. Furthermore the fact that NOS immunoreactive neurons were activated suggests that CCK modulates the activity of inhibitory motor neurons in the myenteric plexus. Expression of Fos immunoreactivity in Calr and Cal immunoreactive neurons is consistent with a role for CCK in modulation of intrinsic sensory and/or secretomotor neuronal activity in the submucosal plexus.

BACKGROUND

Anagrelide represents a treatment option for essential thrombocythemia, although its place in therapy remains controversial.

OBJECTIVE

To assess the impact of mutational status in response rates and development of adverse events during long-term use of anagrelide.

METHODS

We retrospectively evaluated 67 patients with essential thrombocythemia treated with anagrelide during 68 (4-176) months.

RESULTS

Mutational frequencies were 46.3%, 28.3%, and 1.5% for JAK2V617F, CALR and MPL mutations. Anagrelide yielded a high rate of hematologic responses, which were complete in 49.25% and partial in 46.25%, without differences among molecular subsets. The rate of thrombosis during treatment was one per 100 patient-years, without excess bleeding. Anemia was the major adverse event, 30.3% at 5-yr follow-up, being more frequent in CALR(+) (P < 0.05). Myelofibrotic transformation developed in 14.9% (12.9%, 21%, and 12.5% in JAK2V617F(+), CALR(+), and triple-negative patients, respectively, P = NS) and those treated >60 months were at higher risk, OR (95% CI) 9.32 (1.1-78.5), P < 0.01, indicating the need for bone marrow monitoring during prolonged treatment.

CONCLUSIONS

Although CALR(+) patients were at higher risk of developing anemia, anagrelide proved effective among all molecular subsets, indicating that mutational status does not seem to represent a major determinant of choice of cytoreductive treatment among essential thrombocythemia therapies.

The cpsQ-mfpABC locus is transcribed as two operons, i.e., cpsQ-mfpABC and mfpABC, in Vibrio parahaemolyticus, and both of them are all required for biofilm formation. CalR belongs to the LysR-type transcriptional regulator family, and was originally identified as a repressor of the swarming motility and T3SS1 genes expression in V. parahaemolyticus. In the present work, a combination of qRT-PCR, primer extension, LacZ fusion expression, electrophoretic mobility shift assay, and DNase I footprinting assays were employed to elucidate the regulatory mechanisms of cpsQ-mfpABC and mfpABC by CalR. One transcription start site for each operon was detected and their activities were activated by CalR. His-CalR protected two DNA regions upstream of mfpABC against DNase I digestion, but no binding sites were detected in the promoter region of cpsQ-mfpABC, suggesting a direct and an indirect regulatory manner for mfpABC and cpsQ-mfpABC transcription by CalR, respectively. Collectively, the results presented here confirmed a new physiological role for CalR that acts as an activator for cpsQ-mfpABC and mfpABC transcription.

In myelofibrosis (MF), driver mutations in JAK2, MPL, or CALR impact survival and progression to blast phase, with the greatest risk conferred by triple-negative status. Subclonal mutations, including mutations in high-molecular risk (HMR) genes, such as ASXL1, EZH2, IDH1/2, and SRSF2 have also been associated with inferior prognosis. However, data evaluating the impact of next-generation sequencing in MF patients treated with JAK1/2 inhibitors are lacking. Using a 54-gene myeloid panel, we performed targeted sequencing on 100 MF patients treated with ruxolitinib (n = 77) or momelotinib (n = 23) and correlated mutational profiles with treatment outcomes. Ninety-nine patients had at least 1 mutation identified, 46 (46%) had 2 mutations, and 34 (34%) patients had ≥3 mutations. Seventy-nine patients carried a mutation in JAK2V617F, 14 patients had mutations in CALR, 6 patients had an MPL mutation, and 2 patients were triple negative. No mutation was significantly associated with spleen or anemia response. A high Dynamic International Prognostic Scoring System score and pretreatment transfusion dependence were associated with a shorter time to treatment failure (TTF), and this association retained significance on multivariable analysis. Patients with ASXL1 (hazard ratio [HR], 1.86; P = .03) and EZH2 mutations (HR, 2.94; P = .009) and an HMR profile (HR, 2.06; P = .01) had shorter TTF. On multivariate analysis, ASXL1 or EZH2 mutations were independently associated with shorter TTF and overall survival. These findings help identify patients unlikely to have a durable response with current JAK1/2 inhibitors and provide a framework for future studies.

Discovery of somatic mutations in the calreticulin gene (CALR) has identified a subgroup of Philadelphia-negative chronic myeloproliferative neoplasms (MPN) with separate haematological characteristics and prognosis. CALR mutations serve as novel markers both of diagnostic value and as targets for monitoring molecular responses during therapy. Interferon-α (IFN) selectively targets the malignant clone in a subset of MPN patients and can induce both haematological and molecular remissions in CALR mutated essential thrombocythemia (ET) patients. We investigated the response to IFN in a cohort of 21 CALR mutated MPN patients including ET, prefibrotic primary myelofibrosis (pre-PMF), and primary myelofibrosis (PMF) with a median follow-up of 31 months. For evaluation of a molecular response, we developed highly sensitive quantitative PCR (qPCR) assays for monitoring the mutant allele burden of the two most prevalent CALR mutations (type 1 and type 2). Thirteen patients (62%) experienced a decrease in the mutant allele burden with a median decline of 29% from baseline. However, only four patients, including patients with ET, pre-PMF, and PMF diagnosis, achieved molecular responder (MR) status with >50% reduction in mutant allele burden according to European LeukemiaNet (ELN) guidelines. MR patients displayed significant differences in the dynamics of the CALR mutant load with regard to time to response and dynamics in mutant allele burden after discontinuation of IFN treatment. Furthermore, we highlight the prognostic value of the CALR mutant allele burden by showing a close association with leucocyte- and platelet counts, hemoglobin concentration, in addition to plasma lactate dehydrogenase (LDH) irrespective of molecular response and treatment status.

Although numerous studies have shown the cancer-preventive properties of butylidenephthalide (BP), there is little report of BP affecting human prostate cancer cells. In the present study, proteomic-based approaches were used to elucidate the anticancer mechanism of BP in LNCaP human prostate cancer cells. BP treatment decreased the viability of LNCaP human prostate cancer cells in a concentration- and time-dependent manner, which was correlated with G0/G1 phase cell cycle arrest. Increased cell cycle arrest was associated with a decrease in the level of CCND1, CDK2, and PCNA proteins and an increase in the level of CDKN2A, CDKN1A, and SFN proteins. Proteomic studies revealed that among 48 differentially expressed proteins, 25 proteins were down-regulated and 23 proteins were up-regulated and these proteins fall into one large protein protein interaction network. Among these proteins, FAS, AIFM1, BIK, CYCS, SFN, PPP2R1A, CALR, HSPA5, DDIT3, and ERN1 are apoptosis and endoplasmic reticulum (ER) stress associated proteins. Proteomic data suggested that multiple signaling pathways including FAS-dependent pathway, mitochondrial pathway, and ER stress pathway are involved in the apoptosis induced by BP.

BACKGROUND

Somatic mutations in Calreticulin (CALR) have been recently discovered in JAK2/MPL unmutated patients with primary myelofibrosis (PMF) or essential thrombocythemia.

METHODS

Clinical and hematologic features were obtained for 80 patients with PMF. JAK2V617F mutation was analyzed by DNA tetra-primer amplification refractory mutation system (ARMS-PCR). CALR and MPL mutations were identified by bi-directional Sanger sequencing.

RESULTS

CALR mutations were detected in 11.2% (9/80) of all PMF patients and 25.7% (9/35) of all JAK2V617F and MPL unmutated patients all of which were Type I mutation or deletions. A novel CALR mutation pattern (c.1241_1288del) was identified in one (1/9) patient. No case of Type II mutations or scattered point mutations was found in any of these patients. Uni-variate analysis at presentation showed that CALR mutations were significantly associated with younger age (P = 0.003) and larger spleen size (P = 0.001). No significant correlation was found between CALR mutation and clinico-hematologic characteristics or international prognostic scoring system (IPSS) scoring of the PMF patients.

CONCLUSIONS

CALR mutations have a distinct molecular profile in Indian patients, different from that of other studies worldwide. Larger prospective studies need to be designed to establish the impact of paucity of Type II mutations in contributing to disease phenotype and prognostic outcome of patients.

BACKGROUND

The majority of patients with JAK2 V617F-negative essential thrombocythemia or primary myelofibrosis harbor mutations involving the calreticulin (CALR) gene. These mutations are located in CALR exon 9 and lead to a frameshift with subsequent alteration of the CALR protein C-terminus. They have emerged as valuable molecular markers for the diagnosis of clonal myeloproliferative diseases. Although a variety of CALR mutations have been described, two mutations, denoted type 1 and type 2, account for around 85 % of cases. The type 1 mutation encompasses a 52 bp deletion and the type 2 mutation a 5 bp TTGTC insertion.

METHODS

This work describes the development and testing of quantitative real-time PCRs (qPCRs) for detecting these two mutations.

RESULTS

The final type 1 CALR qPCR displayed a sensitivity of <0.1 % mutant alleles and the type 2 CALR qPCR had a sensitivity of <0.01 % mutant alleles. Additionally, two new CALR mutations are reported.

CONCLUSIONS

These sensitive and specific qPCRs should be helpful in establishing the diagnosis and in monitoring minimal residual disease in patients during or after therapy.

OBJECTIVE

CML, PV, ET and PMF are so called classical MPN with distinct clinical phenotypes. The discovery of the BCR-ABL1 translocation and mutations in driver genes JAK2, MPL and CALR has provided novel insights in their pathogenesis. While these mutations are thought to be mutually exclusive, rare cases of MPN with coexisting driver mutations have been reported. However, little is known about the clinical, biological and molecular characteristics of these patients and the interaction of the neoplastic clones.

METHODS

We retrospectively studied 11 MPN patients with coexisting driver mutations (JAK2 V617F + BCR-ABL1: n = 8; CALR type 2 + BCR-ABL1: n = 1; JAK2 V617F + MPL W515: n = 1; JAK2 V617F + CALR type 1: n = 1). To assess possible associated molecular aberrations, we analysed DNA of six patients using NGS.

RESULTS

In four CML patients, decreasing BCR-ABL1 transcript levels with increasing JAK2 V617F allele burden under TKI were observed. This strongly suggests that the coexistence of driver mutations originates from two different clones growing independently. Additional somatic mutations were detected in 5 out of 6 (83%) patients affecting 4 different genes, confirming the heterogeneity of this study cohort. Suboptimal response to TKI was observed with a higher frequency (4/8 patients) than reported in conventional series of CML and the overall tolerance of treatment with hydroxyurea and/or imatinib in our series was poor.

CONCLUSIONS

Given the emergence of NGS in clinical practice, more similar cases will be identified in the coming years. The optimal treatment strategy for this rare group of patients is uncertain and toxicity of combination treatment may have to be considered.

Tissue-specific expression of the CALR gene in the brain gray matter in late-adolescence and early adulthood coincides with the expression of the psychoses phenotypes. Indeed, increased expression of the chaperone genes in the prefrontal cortex has been reported in patients affected by schizophrenia. We have previously reported cases of psychosis-associated mutations in the CALR gene promoter. One of those mutations at -48 was found to increase the expression of the gene in comparison with the wild type sequence. A recently identified mutation at -220 reverts the conserved block harboring nucleotide -220 to the ancestral type, and has an approximate prevalence of 0.7% in psychoses. In this study, we analyzed the functional implication of this mutation in the human neuroblastoma cell line BE(2)-C, and non-neural Human Embryonic Kidney 293 (HEK-293), and show that the -220A mutation results in a constitutive increase in the expression of the CALR gene (p<0.0003). We checked homology of the first 1000-bp CALR promoter sequence across species, and found that nucleotide -220C is the only human-unique nucleotide in that stretch. The -220A mutation, on the other hand, co-occurs with severe cognition deficit in humans, and is the rule across the species except humans. To our knowledge, the -220A mutation is the first reported instance of a cognition-deficit-associated mutation which reverses a human gene promoter to the primitive type. It may be speculated that, at least the basal transcription of the CALR gene, relating to the proximal promoter region, has been decreased during the process of evolution to humans.

OBJECTIVE

Myeloproliferative neoplasms (MPN) are a heterogeneous group of clonal proliferative bone marrow diseases characterised by extensive megakaryocytic hyperplasia and morphological atypia. Despite knowledge of genomic defects, the pathobiological processes driving these megakaryocytic abnormalities in MPN remain poorly explained. We have explored the proliferative, apoptotic and epigenetic profiles of megakaryocytes in human MPN.

METHODS

Immunohistochemical staining was performed on bone marrow trephine biopsies of 81 MPN (with and without JAK2(V617F) and CALR mutations) and 15 normal controls to assess the megakaryocytic expression of biomarkers associated with proliferation (Ki67), apoptosis (Bcl-XL, BNIP-3) and epigenetic regulation (EZH2, SUZ12).

RESULTS

Myeloproliferative megakaryocytes showed significantly greater expression of proliferative Ki67 and anti-apoptotic Bcl-XL, reduced pro-apoptotic BNIP-3 and increased SUZ12 compared with controls. In essential thrombocythaemia, large-giant megakaryocytes with hyperlobated nuclei showed a trend towards a proliferative signature. In contrast, myelofibrotic megakaryocytes with condensed nuclear chromatin, and cases with CALR mutations, had significant reductions in pro-apoptotic BNIP-3.

CONCLUSIONS

Uncontrolled megakaryocytic expansion in MPN results from a combination of increased proliferation, attenuated apoptosis and defective epigenetic regulation with CALR mutations favouring apoptotic failure. The higher platelet counts reported to be seen in MPN with CALR mutations may be due to greater dysregulation of megakaryocyte apoptosis.

Somatic mutations in the CALR gene have been recently identified as acquired alterations in myeloproliferative neoplasms (MPNs). In this study, we evaluated mutation frequencies, laboratory features, and granulocyte activation in Chinese patients with MPNs. A combination of qualitative allele-specific polymerase chain reaction and Sanger sequencing was used to detect three driver mutations (i.e., CALR, JAK2V617F, and MPL). CALR mutations were identified in 8.4% of cases with essential thrombocythemia (ET) and 5.3% of cases with primary myelofibrosis (PMF). Moreover, 25% of polycythemia vera, 29.5% of ET, and 48.1% of PMF were negative for all three mutations (JAK2V617F, MPL, and CALR). Compared with those patients with JAK2V617F mutation, CALR-mutated ET patients displayed unique hematological phenotypes, including higher platelet counts, and lower leukocyte counts and hemoglobin levels. Significant differences were not found between Chinese PMF patients with mutants CALR and JAK2V617F in terms of laboratory features. Interestingly, patients with CALR mutations showed markedly decreased levels of leukocyte alkaline phosphatase (LAP) expression, whereas those with JAK2V617F mutation presented with elevated levels. Overall, a lower mutant rate of CALR gene and a higher triple-negative rate were identified in the cohort of Chinese patients with MPNs. This result indicates that an undiscovered mutant gene may have a significant role in these patients. Moreover, these pathological features further imply that the disease biology varies considerably between mutants CALR and JAK2V617F.

UNASSIGNED

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive gastrointestinal cancer characterized by an extremely low survival rate because of early metastasis. Identifying satisfactory therapeutic targets associated with metastasis is crucial to improve the treatment effect of PDAC.

UNASSIGNED

In this research, we used stable isotope labeling by amino acids in cell culture, 1-dodecyl-3-methylimidazolium chloride-assisted sample preparation method preparing protein sample and nano-reversed-phase liquid chromatography-mass spectrometry/mass spectrometry analysis to perform the comparative proteomics of two homologous hamster pancreatic cancer cell lines that are different in metastatic ability: PC-1.0 (highly metastatic) and PC-1 (weakly metastatic). Verifications are through immunohistochemistry on clinical human PDAC pathologic tissues as well as by Western blot of human pancreatic cancer cell lines. siRNA silencing methods were used to study the effect of molecules on invasion and metastasis of pancreatic cancer cell lines.

UNASSIGNED

Bioinformatic analysis indicated that a total of 141 differentially expressed proteins (82 upregulated and 59 downregulated in PC-1.0 cells) were identified showing obviously differential expression (>1.5-fold change). These differentially expressed proteins were involved in a number of different biologic functions, metabolic pathways, and pathophysiologic processes. Phosphoglycerate mutase 1 (PGAM1) and HSPE1 are the top two upregulated proteins, and PDIA3 and CALR are the top two downregulated proteins in PC-1.0 cells compared to PC-1 cells. PGAM1 and HSPE1 showed higher expressions in PDAC tissue with clinical metastasis and highly metastatic pancreatic cancer cell lines PC-1.0 and Aspc-1. PDIA3 and CALR showed higher expressions in weakly metastatic pancreatic cancer cell lines PC-1 and Capan-2. The Western blot results were consistent with the MS quantification data. Silencing PGAM1 was found to decrease the migration and invasion of pancreatic cancer cell lines with statistical significance, especially in highly metastatic PC-1.0 and Aspc-1 cell lines.

UNASSIGNED

These data indicated that PGAM1 may be a potential therapeutic target for PDAC metastasis.

Comparative proteomic analyses were performed in adipose tissue of leptin-deficient ob/ob mice treated with leptin or control buffer in order to identify the protein expression changes as the potential targets of leptin. Mice were treated with either phosphate-buffered saline (control) or 10 µg/day leptin for 14 days via subcutaneous osmotic minipumps. Total protein from white adipose tissue was extracted and labeled with different fluorescent cyanine dyes for analysis by two-dimensional difference gel electrophoresis (DIGE). Spots that were differentially expressed and appeared to have sufficient material for mass spectrometry analysis were picked and digested with trypsin and subjected to MALDI-TOF MS for protein identification. Twelve functional protein groups were found differentially expressed in adipose tissue of leptin-treated vs. control ob/ob mice, including molecular chaperones and redox proteins such as calreticulin (CALR), protein disulfide isomerase-associated 3 (PDIA3), prohibitin (PHB), and peroxiredoxin-6 (PRDX6); cytoskeleton proteins such as β actin, desmin, and α-tubulin; and some other proteins. The mRNA levels of CALR, PDIA3, and PHB were measured by real-time reverse transcription-PCR and found to be upregulated (P < 0.05), consistent with the fold change in protein expression level. Our findings suggest that leptin's effects on lipid metabolism and apoptosis may be mediated in part by alterations in expression of molecular chaperones and redox proteins for regulating endoplasmic reticulum stress and cytoskeleton proteins for regulating mitochondrial morphology.

In this study, our goal was to evaluate whether the expressions of microRNA (miR)-150, miR-146b, miR-31 and miR-95 demonstrate primary myelofibrosis (PMF) specificity, associations with fibrosis grade, hematologic phenotypes, or myeloproliferative neoplasm (MPN)-associated mutations. A total of 51 formalin-fixed and paraffin-embedded bone marrow MPN samples, including 15 polycythemia vera (PV), 26 essential thrombocythemia (ET), and 10 PMF, and 24 normal controls were included. The expression of microRNA (miRNA) was detected by quantitative real-time polymerase chain reaction using miRNA specific primers. RNU6-2 was analyzed for all samples as endogenous control for relative quantification. Information for fibrosis, hematologic parameters, Janus kinase 2 (JAK2) V617F, and calreticulin (CALR) mutations was obtained from medical records. Significant increment of miR-146b was detected in PMF compared to normal controls (P=0.008). Moreover, expression of miR-146b tended to increase according to increment of fibrosis grade, and patients with myelofibrosis (MF) grade 3 showed significantly higher expression than patients with MF 0 to 2 (P=0.022, 0.001 and 0.013, respectively) or normal controls (P<0.001). The expression of miR-31 also showed tendency to increase following fibrosis and miR-150 showed up-regulated expression in ET (P=0.015) compared to normal control. There was no relationship between miRNA expression and hematologic indices except miR-95 showed negative correlation with platelet count (P=0.024). There was no significant correlation between miRNA expression and JAK2 V617F or CALR mutation. Up-regulation of miR-146b could be used as a fibrosis-indicating marker and might be helpful in the study of fibrotic mechanism in MPN, as well as other fibrotic diseases.