PTPA and chronic myelogenous leukemia, BCR-ABL1 positive: Whereas in vivo data have confirmed the involvement of SET, SETBP1, and CIP2A proteins in leukemic transformation process, so far we could not rule out the contribution to the development of hematological malignancies of other molecules that have been proven to inhibit PP2A including TIP, ANP32A, and ENSA. Recently, one study has reported that knock-down of the NM23-H1 factor in CML K562 cell line decreased proliferation and altered the expression of ANP32A, a potent and selective PP2A inhibitor (37).