Using an integrative analysis based in SNP, mRNA arrays and expression profile of 250 mature miRNAs, together with bioinformatics and functional studies, we found that miR-370, located in a recurrent amplified region, was upregulated and that its target gene was the tumor suppressor NF1. Interestingly, functional analysis showed that overexpression of miR-370 has similar effects that NF1 inactivation, suggesting a leukemogenic role of miR-370 through NF1 downregulation in AML cells. The gene discussed is NF1; the disease is acute myeloid leukemia.