Prostate cancer (PC) has become the most common non-dermatologic cancer among Western men.[1] Due to prostate-specific antigen (PSA) screening efforts, increasing numbers of PC cases are diagnosed when the tumor is still confined to the prostate.[2] The prolonged natural history of the disease as well as the potential risk of progression into metastasis and death must be taken into consideration during the initial management of newly-diagnosed PC. Here, KLK3 is linked to Familial prostate cancer.