CD99 is expressed on all leukocytes but highest on thymocytes and is believed to augment T-cell adhesion and apoptosis of double positive T cells, and has been found in endothelial cells and in the periodontium, including gingival fibroblasts and gingival epithelial cells, as well as participates in migration and activation.
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. 
