NDUFB9 is a 179 amino acid protein that belongs to the complex I LYR family. Localized to the inner mitochondrial membrane, as well as to the matrix side of the peripheral membrane, NDUFB9 functions as an accessory subunit of the multi-subunit mitochondrial membrane respiratory chain NADH dehydrogenase complex I. Complex I plays an important role in the transfer of electrons from NADH to the respiratory chain, a process that is essential for cellular respiration. The gene encoding NDUFB9 maps t