3.mAbs blocking inhibitory checkpoints in NK cells - The disruption of PD1/PD-L1 interactions unleashes both PD1+ T and NK cells. Major effect of NK cells in case of HLA-Cl-I− tumors (20–24); - Blocking of NKG2A expressed by both NK and tumor-infiltrating T cells results in killing of HLA-E+ tumors (i.e., most tumors) (25, 26); - Combined blocking of NKG2A and PD1 in case of PD-L1+ tumors (25, 26); - Combined use of NKG2A-blocking mAb and mAb specific for tumor antigens (e.g., EGFR): “unlocked” NK cells mediate ADCC (25, 26). Here, HLA-E is linked to neoplasm.