TP53 and Familial prostate cancer: Although our GWAS was restricted to men without prostate cancer, several cancer susceptibility genes were among the PSA-associated loci, including a pan-cancer risk variant in TP53 (rs78378222) (ref.49) and signals in TP63, GPC3 and THADA. Although we cannot rule out undiagnosed prostate cancer in our participants, its prevalence is unlikely to be high enough to produce appreciable bias.