PTPRD (Protein tyrosine phosphatase receptor type D) is a member of the protein tyrosine phosphatase (PTP) family that plays diverse roles during development including cell growth, differentiation, mitotic cycle and oncogenic transformation. PTPRD contains an extracellular region, a single transmembrane segment and two tandem intracytoplasmic catalytic domains. The extracellular region of PTPRD is composed of three Ig-like and eight fibronectin type III-like domains. PTPRD interacts with PPFIA1-3 and is a tumor suppressor on chromosome 9p that is involved in the development of glioblastoma multiform (GBMs) and multiple human cancers.