Thy-1 membrane glycoprotein (also known as CD90) was identified as an activation-associated cell adhesion molecule on human dermal microvascular endothelial cells. Its cellular effects vary; however, it most often seems to affect cell-cell or cell-matrix interactions and cellular adhesion and migration [, ]. Thy-1 interacts with the leukocyte integrin Mac-1 and may play an important role in the regulation of leukocyte recruitment to sites of inflammation []. It also plays an important role in normal retinal development [].