In humans, LEP (7q32.1) encodes a protein responsible to regulate energy homeostasis. The protein is related to bone metabolism since is a potent inhibitor of bone in vivo (Elefteriou et al., 2004). In female mice, the protein promotes the transdifferentiation of vascular smooth muscle cells to osteoblasts by increasing RANKL expression (Liu et al., 2014) In humans, mutations in LEP gene cause morbid obesity (Montague et al., 1997). Here, LEP is linked to morbid obesity.