Similarly, Pegram and colleagues transfected full-length human HER2/neu cDNA into MCF7, MDA-MB-231, MDA-MB-435, and BT-20 breast cancer cell lines and two ovarian cancer cell lines and compared the response of these cell lines in vitro and in vivo to that of mock-transfected parental lines106. The gene discussed is ERBB2; the disease is breast carcinoma.