After PPI analysis, 22 hub genes related to ccRCC stood out, among which CD4, PTPRC, CCNA2, CD8A, BUB1, ASPM, BUB1B, KIF20A, CENPF, DLGAP5, ITGB2, KIF2C, TYROBP, BIRC5, CEP55, ITGAM, MELK, NUSAP1, and TPX2 were found to differentially methylated genes between ccRCC tissues and paired tumor-free kidney tissues. The gene discussed is CD8A; the disease is neoplasm.