GATA3 and breast cancer: The degree of AR and GATA3 co-occupancy following treatment with DHT was also high in the ER- breast cancer cell lines, representing 80% of GATA3 binding sites in MDA-MB-453 and 60% in MFM-223 cells (Fig. 4D; Additional file 2: Fig. S5 A-C; Additional file 4).