PTPN7 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. PTPN7 is preferentially expressed in a variety of hematopoietic cells, and is an early response gene in lymphokine stimulated cells. The noncatalytic N-terminus of this PTP can interact with MAP kinases and suppress the MAP kinase activities. This PTP has been shown to be involved in the regulation of T cell antigen receptor (TCR) signaling, which is thought to function through dephosphorylating the molecules related to MAP kinase pathway.