Background：

The protein encoded by this gene is a member of the protein tyrosine phosphatase (PTP) family. PTPs are known to be signaling molecules that regulate a variety of cellular processes， including cell growth， differentiation， mitotic cycle， and oncogenic transformation. This PTP possesses an extracellular region containing five fibronectin type III repeats， a single transmembrane region， and a single intracytoplasmic catalytic domain， and thus represents a receptor-type PTP. This protein is present in all hematopoietic lineages， and was shown to negatively regulate T cell receptor signaling possibly through interfering with the phosphorylation of Phospholipase C Gamma 1 and Linker for Activation of T Cells. This protein can also dephosphorylate the PDGF beta receptor， and may be involved in UV-induced signal transduction. Multiple transcript variants encoding different isoforms have been found for this gene.