Metformin's association with decreased risk of prostate cancer has been reported in multiple clinical studies.17, 18, 19 Studies also indicate that it may be a promising chemotherapeutic alternative for metastatic castration-resistant prostate cancer.20 Our previous study demonstrated that metformin suppressed prostate cancer growth in vitro and c-Myc-driven prostate epithelial malignant transformation in vivo. The gene discussed is MYC; the disease is Familial prostate cancer.