GDF15 and sarcopenia: Prior to the discovery of the GDF15 receptor, Borner et al. made the notable observation that neurosurgical ablation of the area postrema (AP), but not subdiaphragmatic vagal deafferentation, reduces the anorexia, weight loss, and sarcopenia observed in a rat hepatoma allograft model of cachexia which we now know to be consistent with a key role for GDF15 acting via its receptor, GFRAL (130).