GATA3, a zinc-finger transcription factor belonging to the GATA family,1, 2 is first identified to be critical in T-cell differentiation.2, 3 Later on, it is discovered to have pivotal roles in development of various human organs.4, 5, 6, 7, 8, 9 The association of GATA3 with human malignancies has been reported in breast cancers, neuroblastomas, endometrial carcinomas, urothelial carcinomas and soft tissue sarcomas.10, 11, 12, 13, 14 However, its function remains elusive. This evidence concerns the gene GATA3 and breast cancer.