CD8A and cancer: These tumor antigen‐loaded DCs can increase the tumor antigen‐specific CD8+ cytotoxic T‐lymphocytes (CTLs), thus enhancing immune responses.100, 101 Of notable interest, the direct activation of T cells by cancer exosomes has not been reported, CD8+ cytotoxic T‐cell stimulatory function of cancer exosomes requires uptake and processing tumor antigens by DCs.100, 102, 103