Myostatin is a member of transforming growth factor beta (TGF-β) superfamily that signals by binding to activin type II receptor, resulting in the recruitment of either ALK3 or ALK4 coreceptor, and activation of SMAD2/3 (Kondás et al.). It is released by myocytes and inhibits muscle growth and ability to regenerate (Lee & Lee). Myostatin appears to affect the lipid catabolic metabolism of adipocytes and inhibits preadipocyte differentiation, as demonstrated in the 3T3-L1 cell line (Li et al.).