Onset of cachexia leads to unfolded protein response (ER stress), including overproduction of several cytokines like TNFα, IL-1, and IL-6, and can activate different critical cancer-associated regulatory pathways by activating key signaling molecules like NF-κB, STAT3, IGF-1, AKT, mTOR and many others [104,105,106,107]. Here, STAT3 is linked to cancer.