Carpten et al. identified RNASEL as a candidate prostate cancer susceptibility gene located within the Hereditary Prostate Cancer 1 (HPC1) linkage peak on chromosome 1q on the basis of evidence that two inactivating mutations in the gene, RNASEL:p.Met1Ile and RNASEL:p.Glu265*, segregated with prostate cancer in chromosome 1q–linked pedigrees [15]. The gene discussed is RNASEL; the disease is Familial prostate cancer.