Based on genomic analysis, KRAS, CHEK2, BARD1, BRCA1, and BRCA2 [57], the DNA mismatch repair (MMR) genes MLH1, MSH2, MSH6, and PMS2 [58], and CDKN2A, NBN, SMAD4, ATM [59], PALB2 [60] STK11 [61], TP53, and MUTYH/MYH [62] are some of the genes associated with PC. The gene discussed is SMAD4; the disease is pachyonychia congenita.