KLK4 and benign prostatic hyperplasia: However, there was no significant difference between KLK4 staining intensity in BPH as compared to Gleason 5 cancer (P = 0.117), or in PIN versus Grade 3 (P = 0.909), Grade 4 (P = 0.667) or Grade 5 (P = 0.159) PCas (one‐way ANOVA; Table S3).