Protein tyrosine phosphatase which stimulates progression from G1 into S phase during mitosis. May play a role in the development and maintenance of differentiating epithelial tissues. Enhances cell proliferation, cell motility and invasive activity, and promotes cancer metastasis. H2O + O-phospho-L-tyrosyl-[protein] = L-tyrosyl-[protein] + phosphate Inhibited by sodium orthovanadate and pentamidine. Homotrimer. Interacts with ATF5 (By similarity). Interacts with tubulin. And mitotic spindle. Expressed in bone marrow, lymph nodes, T lymphocytes, spleen, thymus and tonsil. Overexpressed in tumor cell lines. Expressed in fetal liver. Strongly down-regulated upon tetrodotoxin treatment. Farnesylated. Farnesylation is required for membrane targeting. Unfarnesylated forms are shifted into the nucleus. Belongs to the protein-tyrosine phosphatase family.