KLK3 and Familial prostate cancer: In the multivariate analysis, the clinically significant prostate cancer diagnosis rate was significantly increased with low vitamin D levels (OR, 0.944; P = 0.027) and other factors such as old age (OR, 1.026; P = 0.032), high PSA levels (OR, 1.077; P = 0.001), and small prostate total volume (OR, 0.933; P < 0.001) (Table 3B).