NDUFS3 also known as CI-30 is one of about 45 subunits comprising complex I of the oxidative phosphorylation electron transport chain. NDUFS3 plays a critical role as one of approximately 45 subunits that constitute complex I of the oxidative phosphorylation electron transport chain, which is essential for ATP production in mitochondria. NDUFS3 is located within the inner mitochondrial membrane, where NDUFS3 facilitates the transfer of electrons from NADH to ubiquinone, a key step in cellular respiration. Proper functioning of NDUFS3 is vital for maintaining energy homeostasis, and NDUFS3 dysfunction can lead to severe metabolic disorders, including optic atrophy, Leigh syndrome, and complex I deficiency.