CD8A and neoplasm: However, since the hPBMC employed in the present investigation were not HLA-matched with the tumor cells, it is possible that the effector cells may be unconventional T cells, such as natural killer T cells, gamma-delta (γδ) T cells or mucosal-associated invariant T cells, all of which can express CD8, and, given the non-classical element of our in vitro model, as more recent analyses have shown that innate lymphocytes are novel targets of ICIs68,73,74.