– TSPAN31 is a member of the transmembrane 4 superfamily. Most members of this family are cell-surface proteins that are characterized by the presence of four hydrophobic domains. They mediate signal transduction events that play a role in the regulation of cell development, activation, growth and motility. TSPAN31 is thought to be involved in growth-related cellular processes. This gene is associated with tumorigenesis and osteosarcoma.