1) we discovered that the expression of APA writers CPSF1, CPSF4 and PABPN1 were enriched in Writer_Cluster1 with better prognosis whereas m6A writers METTL14, WTAP and ZC3H13 did the exact opposite, indicating that APA and m6A might be the decisive types of RNA modification in PC pathogenesis. The gene discussed is CPSF4; the disease is pachyonychia congenita.