This is of particular interest, especially considering that the abnormal activation of the signaling pathway downstream of the activin receptors is now known to play a role in the regulation of muscle and bone interaction, and that several ACVR2 ligands, including activin A, activin B, myostatin and GDF-11, have been reported to exert effects on both muscle and bone homeostasis, thereby contributing to the development of overt cachexia [147,219]. This evidence concerns the gene MSTN and Cachexia.