Effect of HDC plus IL2 on NK cells of AML patients. A) Representative dot plots of the CD56^bright and CD56^dim NK cell subpopulations from an AML patient treated with histamine+IL2 before and after treatment. B) Absolute cell numbers of CD56^bright NK cells of 7 AML patients before and after treatment, *** p<0.01. C) Follow-up of NKp44 and KIR expression after HDC plus IL-2 therapy. Shown are histograms for NKp44 and KIR expression on total CD56⁺ CD3^- NK cells of one patient representative for the majority of patients tested.