Among the most promising, we assessed the role of c-myc, which is expressed at every stage of cancer development and is one of the most common upregulated genes in PC [25,26], and of the enhancer of Zeste (both EZH1 and EZH2), the catalytic subunit of the Polycomb repressive complex 2 (PRC2), again a gene strongly upregulated in PC [27,28], and also involved in the c-myc regulation [29,30]. This evidence concerns the gene MYC and pachyonychia congenita.