TNF and sarcopenia: Aging is associated with a chronic state of systemic low‐grade inflammation, characterized by increased plasma levels of pro‐inflammatory mediators like TNF‐α and IL‐6, which are able to stimulate proteolysis mainly via UPR, as previously described for cancer cachexia.154, 156, 157, 158, 159, 160, 161, 162 However, the role of UPR in sarcopenia is still contentious.163, 164, 165 Some studies have described an up‐regulation of components of the UPR in sarcopenia while other have shown a down‐regulation or no differences.166, 167, 168, 169, 170