MTHFD1L and pachyonychia congenita: Transcriptome‐wide association study analysis identified several novel candidate genes for PC, such as RP11‐65J3.1, PPFIBP2, GEMIN4, NIPA2,RNASEH2B, FARS2, MTHFD1L, F2R, TXNDC15, NDUFA3, CRISPLD2, IQSEC3, and LRP5L.