HLA-C and neoplasm: Unlike T cells, which are MHC-restricted and require sensitization and the presence of a tumor target, NK cells are able to rapidly activate and destroy tumor cells through direct cytotoxicity, formation of proinflammatory cytokines and chemokines, as well as by manifesting ADCC through the membrane receptor FcγRIII (CD16) or the apoptosis axis through TRAIL or Fas/FasL (43, 44).