Cell line/primary blasts/in vivo (THP-1, U937, ER-HoxA9 GMP Cell Lines, the HoxA9 + Meis1 or MLL/AF9 primary leukemia cells.Subcutaneous xenograft tumor mice models, disseminated intravenous xenograft leukemia mice models, patient AML sample engrafted (PDX) mice). This evidence concerns the gene HOXA9 and leukemia.