Three proteins were associated with risk of prostate cancer: GP2, TSPAN1, and FLT3LG [1.29 (1.21–1.36), 1.14 (1.09–1.18), and 0.87 (0.82–0.92)] and three were associated with endometrial cancer: CHRDL2, KLK4, and WFIKKN1 [1.42 (1.21–1.65), 1.41 (1.20–1.65), and 1.42 (1.20–1.68)]. This evidence concerns the gene GP2 and Familial prostate cancer.