Aging, prostate-specific antigen, prostate-specific antigen densities (PSAD), the background of prostate cancer, digital rectal examination, the record of prostatic biopsies, and sixth homeobox clustering and distal-less homeobox 1 overexpression were used to create a first logistic regression approach, which was tested in group 1. The gene discussed is KLK3; the disease is Familial prostate cancer.