AR and pachyonychia congenita: Our results are in line with recent findings by Zaho and co-workers demonstrating AR promoter hypomethylation in CRPC [16], but also add important knowledge by showing hypomethylation in previously un-treated metastasis samples suggesting that AR demethylation may be an earlier cause to AR induction in PC metastases than AR amplification, as AR amplification is generally not observed prior to ADT.