CD8A and breast cancer: Using human and mouse BC cell lines, Fang et al. demonstrated that by interacting with partner effectors, RAB7 and MHC-I molecules, MAL2 augments the endocytosis of MHC-I molecules to the late-stage endosome for degradation, downregulates CD8+ T cell cytotoxicity, and thus weakens immune recognition [26] (Figure 1A).