Mutations in the C-terminus of the Nucleophosmin 1 gene (NPMc+) result in the aberrant export of the encoded protein to the cytoplasm [8] and are found in approximately one third of all adult AML, while Mixed Lineage Leukemias (MLL) are characterized by chromosomal translocations involving the fusions of the N-terminus of the MLL gene with many partner genes such as AF4, AF9, ENL or ELL1 [9, 10]. This evidence concerns the gene NPM1 and acute myeloid leukemia.