PCa+DM: prostate cancer with diabetes mellitus; PCa-DM: prostate cancer without diabetes mellitus; BPH: benign prostatic hyperplasia; HDL: high density lipoprotein; HbA1c: glycated hemoglobin, FBG: fasting blood glucose; PSA: prostate-specific antigen; IGF-1: insulin-like growth factor-1. Here, KLK3 is linked to diabetes mellitus.