Currently, the prostate-specific antigen (PSA) biomarker is commonly used for the screening and detection of PC, but it is also an indicator for a number of benign (not cancerous) conditions, such as benign prostatic hyperplasia (BPH) (OMIM: 600082) and prostatitis (inflammation of the prostate)3,4. Here, KLK3 is linked to benign prostatic hyperplasia.