Relative to White men, AA men with prostate cancer present with higher PSA at presentation, greater overall tumor volumes per ng/ mL of serum PSA, and more aggressive disease (Moul et al., 1999, Moul et al., 1995, Sutcliffe et al., 2012, Sanchez-Ortiz et al., 2006)and experience more than twice the prostate cancer mortality (Siegel et al., 2018). Here, KLK3 is linked to Familial prostate cancer.