KLK3 and cancer: Prostate cancer (PCa) is the most frequently diagnosed cancer among men in high‐income countries and the second most frequently diagnosed cancer in men worldwide.1 Currently, digital rectal examination, serum prostate specific antigen (PSA)—a non‐specific blood test—and trans‐rectal ultrasound‐guided biopsy are the primary diagnostic tools.2 Histological analysis remains the main test for PCa diagnosis and grading, and is the standard procedure used to guide treatment.