At a 95% sensitivity testing threshold, the proportions of unnecessary biopsies that would have been avoided using each test were 11% for PSA alone, 20% for the Prostate Cancer Prevention Trial risk calculator, 26% for PHI, 27% for the derived multiplex 2-gene model, 17% for the derived multiplex 3-gene model, and 23% for MPS compared with 37% for MPS2 and 41% for MPS2+. The gene discussed is KLK3; the disease is prostate cancer.