THOP1 is a metalloendopeptidase ubiquitously distributed in mammalian tissues that catalyzes the degradation of neuropeptides under 20 amino acids 1. It functions as a cytoplasmic peptidase involved in processing intracellular peptides and has been implicated in generating amyloidogenic fragments through proteolysis 1. Beyond peptide metabolism, THOP1 regulates metabolic homeostasis; THOP1-null mice show increased susceptibility to obesity, insulin resistance, and non-alcoholic liver steatosis when fed high-fat diets, suggesting roles in lipid metabolism and glucose control 1. Clinically, THOP1 demonstrates significance across multiple pathologies. Low THOP1 expression in non-small cell lung cancer independently predicts decreased disease-free and overall survival, implicating THOP1 as a potential prognostic biomarker 2. Reduced THOP1 expression in background liver tissue associated with hepatocellular carcinoma predicts worse prognosis 3. THOP1 was identified as part of a diagnostic biomarker panel distinguishing dementia with Lewy bodies from Alzheimer's disease in cerebrospinal fluid 4. A genetic pattern including THOP1 on chromosome 19 shows significant association with late-onset Alzheimer's disease risk, particularly in European populations 5. Additionally, circulating THOP1 levels associate with metabolic complications in type 2 diabetes and hepatic steatosis in Prader-Willi syndrome 6, 7.