We have shown that overexpression of the constitutively activated form of ERBB2 (NeuT) increases the metastatic potential of the two androgen-insensitive human prostate cancer cell lines, DU145 and PC3, but not that of the two androgen-sensitive prostate cancer cell lines, LnCaP and Myc-CaP. The gene discussed is ERBB2; the disease is Familial prostate cancer.