Protein tyrosine phosphatase type IVA 2 (PTP4A2),a member of the protein-tyrosine phosphatase family, is also known as Protein-tyrosine phosphatase 4a2, Protein-tyrosine phosphatase of regenerating liver 2 (PRL-2), PRL2 and PTPCAAX2,which is ubiquitously expressed, with highest levels in skeletal muscle, heart and thymus and over expressed in prostate tumor tissue. PTP4A2 contains one tyrosine-protein phosphatase domain. In contrast to PTP4A1 and PTP4A3, PTP4A2 does not interact with tubulin but RABGGTB.PTP4A2 stimulates progression from G1 into S phase during mitosis and promotes tumors. PTP4A2 can also inhibit geranylgeranyl transferase type II activity by blocking the association between RABGGTA and RABGGTB.The acticity of PTP4A2 is inhibited by sodium orthovanadate and pentamidine.