AOX1 (aldehyde oxidase 1) is a molybdenum-dependent oxidoreductase catalyzing the oxidation of aromatic azaheterocycles and aldehydes with broad substrate specificity 1. The enzyme plays a critical role in xenobiotic metabolism, including bioactivation of prodrugs such as famciclovir to its active antiviral form penciclovir [UniProt]. AOX1 metabolizes N1-methylnicotinamide (MNAM) to generate pyridone metabolites, a process linked to reactive oxygen species (ROS) production and mitochondrial homeostasis 2. In hepatic lipid metabolism, AOX1 upregulation during high-fat diet feeding increases production of N-Me-6-PY and N-Me-4-PY, metabolites that promote de novo lipogenesis and hepatic steatosis; conversely, AOX1 inhibition ameliorates non-alcoholic fatty liver disease 3. AOX1 expression is elevated during osteogenic differentiation of bone marrow mesenchymal stem cells and promotes osteoblast-specific gene expression, suggesting involvement in bone metabolism 4. In non-small cell lung cancer, AOX1 induction through G9a/DNMT1 co-targeting sensitizes tumor cells to chemotherapy and targeted agents 5. AOX1 promoter hypermethylation occurs in lung cancer, with methylation patterns serving as potential biomarkers. These findings establish AOX1 as a key metabolic enzyme with disease relevance in metabolic disorders, cancer biology, and drug metabolism.