Antibody bound to breast cancer cells was detected by flow cytometry (Fig. 2C), and significant quantities of human IgG were detected on the surface of both HER2-overexpressing cell lines following incubation with supernatant from HB1.F3-H2IgG and HB1.F3.Ad-H2IgG NSCs. The gene discussed is ERBB2; the disease is breast carcinoma.