TALLA-1, also known as TSPAN7, 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. TALLA-1 gene is associated with X-linked mental retardation and neuropsychiatric diseases such as Huntington's chorea, fragile X syndrome and myotonic dystrophy. TALLA-1 is a cell surface glycoprotein and may have a role in the control of neurite outgrowth. It is known to complex with integrins.