ENTR1 (endosome associated trafficking regulator 1) is a multifunctional endosomal protein that plays critical roles in membrane trafficking, cellular signaling, and disease pathogenesis. ENTR1 regulates post-endocytic trafficking of membrane receptors, including controlling Fas receptor delivery to lysosomes and termination of apoptotic signaling 1. During Fas-induced apoptosis, ENTR1 is cleaved by caspases, creating a positive feedback loop that amplifies apoptotic signaling 1. The protein also modulates antiviral immunity by stabilizing MAVS through inhibition of NIX-mediated mitophagy, thereby enhancing type I interferon responses against RNA viruses 2. In cancer contexts, ENTR1 demonstrates oncogenic properties, promoting colon cancer growth through regulation of glycolysis and key glycolytic enzymes 3, and enhancing glioblastoma proliferation and invasion while inhibiting TNF signaling pathways 4. Genetic evidence supports ENTR1's causal relevance in type 2 diabetes development 5 and its role as a risk gene in ankylosing spondylitis, particularly affecting natural killer cell function 6. ENTR1 represents a promising therapeutic target across multiple diseases, from metabolic disorders to cancer and autoimmune conditions.