Cytochrome b-c1 complex subunit 6, mitochondrial (UQCRH) belongs to the UQCRH/QCR6 family, it is a subunit of the respiratory chain protein Ubiquinol Cytochrome c Reductase. This is a component of the ubiquinol-cytochrome c reductase complex (complex III or cytochrome b-c1 complex), which is part of the mitochondrial respiratory chain. UQCRH may mediate formation of the complex between cytochromes c and c1. It may mediate formation of the complex between cytochromes c and c1.