Transcription factor GATA-3 is a protein that in humans is encoded by the GATA3 gene.
GATA-3 belongs to the GATA family of transcription factors. It regulates luminal epithelial cell differentiation in the mammary gland. The protein contains two GATA-type zinc fingers and is an important regulator of T cell development and plays an important role in endothelial cell biology. GATA-3 has been shown to promote the secretion of IL-4, IL-5, and IL-13 from Th2 cells, and induces the differentiation of Th0 cells towards this Th2 cell subtype while suppressing their differentiation towards Th1 cells. It is hypothesised that GATA-3 may play tissue-specific roles. It has been suggested that GATA-3 is regulated in CD4+ T cells at a transcriptional level through the IL-4 receptor, as well as translationally through T cell receptor signaling.