Several mechanisms could explain the downregulation of NCRs in some patients: chronic ligands exposure as it has been described for DNAM-1 or NKG2D [29, 45]; or cytokines released by the tumor, such as TGF-β1 which has been shown to downregulate NKp30 and NKG2D [46, 47]. Here, KLRK1 is linked to neoplasm.