Tumour cells are influenced by their microenvironment, which can promote uncontrolled growth, invasion and metastasis. The GATA3 transcription factor is now shown to regulate the tumour microenvironment by inducing the expression of miR-29b in cancer cells. This microRNA in turn inhibits the expression of genes involved in angiogenesis and extracellular matrix signalling and remodelling to suppress metastasis.