Myostatin is a TGF-β family member that acts as an inhibitor of skeletal muscle growth. This muscle-specific cytokine interacts with Activin type I and type II receptors, and suppresses myoblast proliferation by arresting cell-cycle in the G1 phase. Suppression of myostatin activity facilitates muscle formation and may be useful in reducing and/or preventing adiposity and type-2 diabetes. Myostatin activity can be blocked by the Activin-binding protein Follistatin, and by the propeptide of Myostatin. Recombinant Human myostatin is a 25.0 kDa protein consisting of two identical 109 amino acid polypeptides linked by a single disulfide bond.