As observed in AML patients, blood NK cells from MDS patients show severe defects with downregulation of activating receptors, including NKG2D and DNAM-1 (81), reduced cytotoxic activity (81, 82), and increased apoptosis rate in response to IL-2 stimulation associated with reduced proliferation in vitro (82). Here, KLRK1 is linked to acute myeloid leukemia.