Ex vivo stimulation with 10 ng/mL IL-2 or 50 ng/mL IL-15 was reported to be optimal for NK cell expansion and enable NK cells of AML patients with recovered function through upregulating activating receptors such as NKp30, NKp46, NKG2C and NKG2D [188–190]. This evidence concerns the gene KLRK1 and acute myeloid leukemia.