GATA3 induces populations of proliferating mammospheres in breast cancer, but not normal, cells. (A) Representative mammospheres generated following control or GATA3 transfection. A 100 μ bar is shown at each photo. (B) Mammospheres count. Average counts of two independent experiments for each cell type are shown. (*) T-test P-value <0.1. GATA3, GATA binding protein 3.