The importance of its potent inhibitory activity towards PP2a is underlined in its involvement in a form of acute non-lymphocytic myeloid leukemia with t(6,9) and in BCR/ABL-driven leukemias (CML and Ph1-ALL), suggesting that disruption of normal PP2a regulation may also play a role in the pathogenesis of these leukemias [150]. This evidence concerns the gene PTPA and acute lymphoblastic leukemia.