CD8A and cancer: Immune-mediated elimination of intracellular microbes and cancer cells is accomplished by a complex lytic process orchestrated by CD8+ cytotoxic T lymphocytes (CTLs) and NK cells.1, 2, 3 In response to antigen-specific recognition, biochemically defined signaling events triggered by T-cell receptor (TCR)/CD3 engagement and crosslinking of accessory molecules, leads to CD8 T-cell activation and differentiation.