SOST and obesity due to melanocortin 4 receptor deficiency: Matrix Gla protein (MGP), Noggin, Sclerostin (SOST), and Gremlin have been identified as several extracellular, intracellular and transcriptional BMP inhibitors that are upregulated in obesity and act as negative regulators of BMP signaling pathways, ultimately downregulating osteoblastogenesis (Lampropoulos et al., 2012; Roy, 2013).