CD272, a type I transmembrane glycoprotein, contains in its intracellular domain two ITIM sequences, which are upon CD272 triggering phosphorylated and recruit SHP phosphatases to attenuate cell activation. CD272 is expressed on B and T lymphocytes, NK cells, dendritic cells, and macrophages, and its ligand is CD270. Defects in CD272-CD270 inhibitory mechanism lead to autoimmune diseases. Overexpression of CD272 is a marker of tolerant T cells.