Unlike early-stage PC among 60–70-year-old patients and late-stage PC in patients agedbelow 55 years old, CDH2 and CDH4, as well as LIN7A, COL8A1, DSP, GSC, ICAM1, ICAM5, FRAS1, ITGA10, ITGA8, ITGAV, OCLN, PLEC, TJP1, and NPNT, showed a drop in expression, whereas CDH15, CDH26, and CTNNA2 were overexpressed, akin to late-stage PC in patients below 55 years old. The gene discussed is CDH4; the disease is pachyonychia congenita.