IL2 and acute myeloid leukemia: They showed that infusion of NK cells from HLA-haploidentical donors combined with subcutaneous IL-2 administration after a pre-conditioning regimen of high-dose cyclophosphamide and fludarabine resulted in successful in vivo expansion of donor NK cells and the induction of complete remission in 5 out of 19 patients with poor-prognosis acute myeloid leukemia (AML) [5].