Ubiquinol-cytochrome c reductase, complex III subunit VII, 9.5kDa is a protein that in humans is encoded by the UQCRQ gene. This ubiqinone-binding protein is a subunit of mitochondrial Complex III in the electron transport chain. A mutation in the UQCRQ gene has been shown to cause severe neurological disorders. Infection by Trypanosoma cruzi can cause oxidative modification of this protein in cardiac muscle tissue.