Similar findings of overexpression of STEAP4 have been shown in breast cancer HER2+ (human epidermal growth factor receptor 2) cells, where L1 (0.025–0.05 mM) and the HER2+ inhibitor Lapatinib caused significant inhibition of STEAP4 and significant reduction in breast cancer cell growth [272]. The gene discussed is ERBB2; the disease is breast cancer.