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)). This evidence concerns the gene CTSV and pachyonychia congenita.