CD183, also known as CXCR3, is a member of the C-X-C chemokine family, characterized by a pair of cysteine residues separated by a single amino acid. CXCR3 is a 38 kD seven pass transmembrane receptor coupled to G-protein. It mediates Ca2+ mobilibization and chemotaxis in response to C-X-C chemokines, such as IP10 (CXCL10), MIG (CXCL9), I-TAC (CXCL11) and PF4 (CXCL4). CXCR3 is expressed primarily on activiated T lymphocytes, NK cells, and some epithelial cells and endothelial cells. It is not expressed on B cells, monocytes or granulocytes.