DKK1 and pachyonychia congenita: Differential gene expression analyses showed that the seven key genes in the acidosis-related signature (ARNTL2, DKK1, CEP55, CTSV, MYEOV, DSG2, and GBP2) all had higher expression levels in PC tumor specimens than in corresponding normal tissues in GSE62452 (Fig. S3(A)–S3(G)).