CD274 and cancer: For example, exosome membranes fuse with MHC–antigen complexes and induce antigen‐specific T cell responses in the initiation and progression of inflammation.[53] The exosome surface receptors CD86 and lymphocyte function‐associated antigen 1 (LFA‐1) signal inflammatory pathways that activate immune cells.[54] Exosome surface proteins also facilitate immune suppression: exosomes derived from cancer cells that express programmed death‐ligand 1 (PD‐L1), an inhibitory checkpoint molecule, can suppress the function of cytotoxic T cells[55] and promote the immune escape of cancer cells.