The UPR system is specifically up‐regulated by skeletal muscle cells during cancer cachexia through the expression of ubiquitin‐ligases: the muscle RING finger‐containing protein 1 (MURF1) and Atrogin‐1.15, 69, 82, 83 The expression of these ligases involved in muscular proteolysis and muscle wasting is increased by the activation of forkhead box O (FOXO) family transcription factors.3, 15 FOXO activation occurs via NF‐κB signalling, which is activated by cytokines such as TNF‐α and IL‐1 and by proteolysis‐inducing factor (PIF).3, 15, 84. Here, IL1B is linked to cancer.