ubiquinol-cytochrome c reductase complex III subunit VII (UQCRQ) is a ubiquinone-binding protein of low molecular mass. UQCRQ is a small core-associated protein and a subunit of ubiquinol-cytochrome c reductase complex III, which is part of the mitochondrial respiratory chain [taken from NCBI Entrez Gene (Gene ID: 27089)].