– PTP4A2, also known as PRL2 or PTPCAAX2, is short for Protein tyrosine phosphatase type IVA 2. This protein exists in cell membrane, cytoplasm,endosome and membrane. PTP4A2 is often farnesylated during post-translational modification. Farnesylation is required for membrane targeting and for interaction with RABGGTB. The unfarnesylated forms are redirected to the nucleus and cytosol. It can stimulate progression from G1 into S phase during mitosis and promotes tumors. It also inhibits geranylgeranyl transferase type II activity by blocking the association between RABGGTA and RABGGTB.