A phase III trial (the 0201 trial) evaluated the safety and relapse-preventive efficacy of combinatorial immunotherapy with histamine dihydrochloride (HDC) and low-dose interleukin-2 (IL-2) in AML patients after the completion of consolidation chemotherapy.13 The trial recruited 320 adult patients in CR regardless of previous induction or consolidation therapy (excluding previous allo-SCT) and met the primary endpoint of improved leukemia-free survival (LFS, defined as relapse or death, whichever occurred first) at >36 months. This evidence concerns the gene IL2 and leukemia.