KLK3 and pachyonychia congenita: If one were to apply the PBCDR (comparing PC stage II-IV vs. stage I PC, PIN, BPH, and prostatitis) to the 1,378 subjects within this study, 52 of the 92 total biopsies (PPV= 55.3%) would have been positive for PC versus the PSA alone (PPV 44.7%).