KLRK1 and neoplasm: Killing may also be reinforced by the tumor cell expression of NCRs (39) and/or NKG2D ligands (such as MICA, MICB, and ULBPs) (40–42) or by antibody-dependent cell-mediated cytotoxicity (ADCC) mediated by CD16 interacting with antibody-coated tumor cells (43) (Figure 1).