CD99 is a cell surface glycoprotein involved in leukocyte migration, T-cell adhesion, ganglioside GM1 and transmembrane protein transport, and T-cell death by a caspase-independent pathway. In addition, it may have the ability to rearrange the actin cytoskeleton and may also act as an oncosuppressor in osteosarcoma. Cyclophilin A binds to CD99 and may act as a signaling regulator of the protein. [Wiki]
