CDKN2A and pachyonychia congenita: In this study we performed functional testing of a rare private germline CDKN2A 5’UTR c.-201_-198delinsCTTT variant specifically associated with PC which we classified as a potential mutation, after applying a pipeline for functional analysis of 5’UTR variants we recently proposed studying CDKN2A 5’UTR variants in melanoma patients [16,17].