CD99 (CD99 Molecule (Xg Blood Group)) is a Protein Coding gene. Diseases associated with CD99 include Extraosseous Ewing's Sarcoma and Ewing Sarcoma. Among its related pathways are Cell surface interactions at the vascular wall and Response to elevated platelet cytosolic Ca2+.
CD99 antigen, also known as MIC2 or single-chain type-1 glycoprotein, is a heavily O-glycosylated transmembrane protein that is encoded by the CD99 gene in humans. It is expressed on all leukocytes but highest on thymocytes and is believed to augment T-cell adhesion and apoptosis of double positive T cells. It has been found in endothelial cells and in the periodontium, including gingival fibroblasts and gingival epithelial cells. It also participates in migration and activation. There is also experimental evidence that it binds to cyclophilin A.