Based on our previous literature review, cachexia is a complex syndrome connected with several signaling pathways, including TGF-β signaling activation, PI3K/Akt/mTOR signaling, the renin–angiotensin–aldosterone system (RAAS) pathway, myostatin and activin signaling, and the hypoxia/HIF-1 pathway [4]. Here, REN is linked to Cachexia.