Low Molecular Weight Protein Tyrosine Phosphatases (LMW-PTP) are a family of enzymes related to various cellular events, such as cytoskeleton rearrangement, cell growth and modulation of immune response . Overexpression of LMW-PTP has been reported in several tumors and is generally associated with a proliferative phenotype and poor prognosis . The LMW-PTP family has been reported to interact with several tyrosine kinases including PDGF , JAK2 , STAT5 , Insulin receptor, Eph Receptor  and EGF receptor . However, the role of LMW-PTP in CML has not yet been well characterized.