A 68-year-old Mexican male with diabetes mellitus type 2 and systemic arterial hypertension was diagnosed in 2013 with prostate cancer by transurethral resection of the prostate which reported ductal adenocarcinoma not differentiated (Gleason score 9 (4 + 5)) and a prostate-specific antigen of 0.446 ng/dl. This evidence concerns the gene KLK3 and prostate cancer.