NDUFA11 (NADH:Ubiquinone Oxidoreductase Subunit A11): NDUFA11 is a gene that encodes a protein component of mitochondrial complex I, the first and largest enzyme complex in the electron transport chain. It supports complex I assembly, stability, and electron transfer from NADH to ubiquinone, helping generate the proton gradient needed for ATP production through oxidative phosphorylation. Mutations in NDUFA11 can disrupt energy metabolism and contribute to mitochondrial diseases and related disorders.