The family history of prostate cancer was significantly associated with PSA level, such that males with no family history of prostate cancer (M = 1.78) and males with one family member with a history of prostate cancer (M = 1.54) had a significantly lower average PSA level than those with 2 or more family members with a history of prostate cancer (M = 3.84) (p = 0.027). The gene discussed is KLK3; the disease is prostate carcinoma.