CD8A and neoplasm: Furthermore, upregulation of major histocompatibility complex (MHC) molecules, costimulatory molecules, adhesion molecules, and death receptors in tumor cells, surrounding stroma, and vascular endothelium following irradiation can also potentiate CD8+ cytolytic responses (Friedman, 2002; McBride et al., 2004; Demaria et al., 2005; Nesslinger et al., 2007).