GDF-8 Overview GDF-8, or Growth Differentiation Factor 8, is a member of a superfamily of proteins known as transforming growth factor beta (TGF-beta). Also known as myostatin, It is produced in skeletal muscle, and negatively regulates skeletal muscle growth and differentiation by inhibiting myoblast proliferation and differentiation. This function has made GDF-8 an attractive target for therapeutic intervention in medical conditions …