Indeed, the aberrant expression of GDF8 has been observed in many diseases, such as obesity, type 2 diabetes, and preeclampsia (Hittel et al., 2009; Palsgaard et al., 2009; Brandt et al., 2012; Guo et al., 2012). The gene discussed is MSTN; the disease is obesity due to melanocortin 4 receptor deficiency.