GATA3 and cancer: We found that silencing GATA3 nearly abolished proliferative capacity of both ER- models, indicating it is an essential gene in ER- as well as ER+ breast cancer cells (Additional file 2: Fig. S6G), which aligns with their GATA3 dependency scores in the Cancer Dependency Map portal (www.depmap.org) (Additional file 2: Fig. S6H).