According to an epidemiologic study analyzing cancer incidence between 1985 and 2015 in three prefectures in Japan1, prostate cancer (PC) increased gradually before 2000, and quickly in early 2000s, which might be associated with the spread of prostate-specific antigen (PSA) screening, and thereafter remained as one of the most common cancers in Japanese males. The gene discussed is KLK3; the disease is prostate carcinoma.