The anti-KIR2DL1/2/3-mAb-IgG4 targets inhibitory KIR2DL1/2/3 receptors on NK cells and blocks their interaction with human leukocyte antigen (HLA)-C (classical MHC-I), thereby enhancing NK-mediated anti-tumor activity22,23. Here, KIR2DL1 is linked to neoplasm.