Accessory subunit that is involved in the functional assembly of the mitochondrial respiratory chain complex I. Complex I has an NADH dehydrogenase activity with ubiquinone as an immediate electron acceptor and mediates the transfer of electrons from NADH to the respiratory chain. Complex I is composed of 45 different subunits. Interacts with CHCHD4. Belongs to the complex I NDUFB10 subunit family.