When PC patients were stratified according to their clinical phenotypes, PPARγ expression levels were unrelated to the considered demographic and clinical features, and DNMT1 showed only a trend of increased expression towards tumors of lower grades of differentiation (G1: median = 0.55, Q1–Q3 = 0.45–0.57; G2: median = 0.87, Q1–Q3 = 0.62–1.47; G3: median = 0.94, Q1–Q3 = 0.75–1.29; P = 0.06). This evidence concerns the gene PPARG and pachyonychia congenita.