Thereafter, we explored the co-occurrence patterns of CD8A mutation and screened the top ten significant genes with log ration greater than 6, thereby identifying RMND5A, RNF103-CHMP3, CHMP3, CD8B, MRPL35, MAT2A, RGPD1, RGPD2, REEP1, and ANAPC1P1 genes, which co-occurred mutations with CD8A, sharing high mutation frequencies (Figure 6C), and genomic alterations (Figure 6D) in an altered group of pan-cancer datasets. The gene discussed is REEP1; the disease is cancer.