OXNAD1 (oxidoreductase NAD binding domain containing 1) is a mitochondrial protein containing an NAD-binding oxidoreductase domain with emerging roles in metabolic regulation and immune aging. OXNAD1 is transcriptionally regulated by PGC-1α and estrogen-related receptor α (ERRα), key regulators of mitochondrial biogenesis and metabolic homeostasis in skeletal muscle 1. The gene is located within a bidirectional promoter shared with DPH3, and frequent somatic UV-signature mutations in this promoter region have been identified across skin cancers, particularly in basal cell carcinoma (42%) and squamous cell carcinoma (39%), though functional consequences remain unclear 23. OXNAD1 functions as a hub gene in immune aging pathways, with age-related expression variations shared between Asian and Caucasian populations 4. Notably, circular RNA circOXNAD1 derived from hypoxia-treated mesenchymal stem cell exosomes demonstrates neuroprotective effects against spinal cord ischemia-reperfusion injury through a miR-29a-3p/FOXO3a regulatory axis 5. Proteomic analysis indicates elevated OXNAD1 expression in lung metastatic colorectal cancer compared to primary lung adenocarcinomas 6. These findings suggest OXNAD1 participates in mitochondrial metabolism, immune system aging, and stress-responsive cellular protection mechanisms.