KIR2DL1 and acute myeloid leukemia: Phase 1 studies of IPH2101, a human IgG4 mAb against KIR2DL1, KIR2DL-2 and KIR2DL-3, illustrated that blocking KIRs with IPH2101 enhances NK cell cytotoxicity against acute myeloid leukemia (AML) and multiple myeloma (MM) without eliciting autoimmune response.