Tyrosine phosphatase which dephosphorylates or contributes to the dephosphorylation of CTNND1, FLT3, PDGFRB, MET, RET, KDR, LYN, SRC, MAPK1, MAPK3, EGFR, TJP1, OCLN, PIK3R1 and PIK3R2. Plays a role in cell adhesion, migration, proliferation and differentiation. Involved in vascular development. May be involved in the mechanism of contact inhibition of cell growth. Regulator of macrophage adhesion and spreading. Positively affects cell-matrix adhesion. Positive regulator of platelet activation and thrombosis. Negative regulator of cell proliferation. Negative regulator of PDGF-stimulated cell migration; through dephosphorylation of PDGFR. Positive regulator of endothelial cell survival, as well as of VEGF-induced SRC and AKT activation; through KDR dephosphorylation. Negative regulator of EGFR signaling pathway; through EGFR dephosphorylation. Enhances the barrier function of epithelial junctions during reassembly. Negatively regulates T-cell receptor (TCR) signaling. Upon T-cell TCR activation, it is up-regulated and excluded from the immunological synapses, while upon T-cell-antigen presenting cells (APC) disengagement, it is no longer excluded and can dephosphorylate PLCG1 and LAT to down-regulate prolongation of signaling. H2O + O-phospho-L-tyrosyl-[protein] = L-tyrosyl-[protein] + phosphate Monomer. Interacts with CTNNB1 (phosphorylated) and JUP (phosphorylated). Interacts with FLT3 (phosphorylated). Interacts with GAB1 and GRB2 (By similarity). After T-cell stimulation, it is temporarily excluded from immunological synapses. Found at cell borders. Expressed at high levels in brain, kidney, spleen and intestine, and at lower levels in liver, lung, thymus and heart. Expressed at a high level in the myeloid cell line FDC-P2, and at a lower level in the pre-B lymphoid cell line WEHI-231 and the T hybridoma cell line HB21.7.31. Not expressed in the fibroblast cell line NIH3T3 or the erythroid cell line F5-5. Expressed in macrophages. Expressed at 11.5 dpc in presumptive macrophages concentrated in the liver and scattered throughout the embryonic mesenchyme. Expressed at 11.5 and 12.5 dpc in the developing eye and in the ganglia and processes of cranial and spinal nerves constituting the PNS. Belongs to the protein-tyrosine phosphatase family. Receptor class 3 subfamily.