CD8A and colorectal carcinoma: CRC cells frequently display dysregulated OXPHOS and elevated mitochondrial ROS, which promote the secretion of immunosuppressive cytokines (e.g., TGF-β, IL-10) and the polarization of tumor-associated macrophages toward an M2-like phenotype, thereby weakening cytotoxic CD8+ T-cell infiltration and activity (27, 261, 262).