ERG and pachyonychia congenita: Regarding the BCR free-survival analysis of combined PTEN and ERG expression, ERG expression with wild-type PTEN showed the best BCR free-survival among four subgroups (p = 0.016, Fig 2C), suggesting a critical function of ERG with PTEN in PC and that their prognostic association might be stronger when multiplexed with each other, possibly owing to the involvement of a critical pathway of prostate carcinogenesis [11, 13, 17].