IL2 and acute myeloid leukemia: Furthermore, a phase IV clinical trial (NCT01347996) which assessed the efficacy of immunotherapy with histamine dihydrochloride (HDC) and low-dose IL-2 in the post-consolidation phase in AML 84 patients in first complete remission demonstrated an association of AML relapse with HDC/IL-2 treatment-induced accumulation of natural Tregs in the blood (91).