Thy1 is a GPI-anchored, developmentally regulated protein involved in various signaling cascades that mediate neurite outgrowth, T cell activation, tumor suppression, apoptosis, and fibrosis. It is highly expressed on the surface of adult neurons and is thought to play a role in modulating adhesive and migratory events, such as neurite extension. Decreased Thy1 expression is associated with the development of epithelial ovarian cancer, revealing its role as a putative tumor suppressor gene of human ovarian cancer.