According to the minimized in vitro cytolytic differences between donor A and donor B after cytokine stimulation with IL2 and the significant increase in cytolytic activity ex vivo, NK cell transfer in lymphodepletion after chemotherapy or in vivo NK cell stimulation by subcutaneous low-dose and long-term IL2 application should be considered as treatment options in AML patients [3, 33, 34]. Here, IL2 is linked to acute myeloid leukemia.