UQCRH and paraganglioma: UQCRH gene dysfunction might influence tumourigenesis by affecting the superoxide-scavenging activity of the respiratory chain, resembling the hypothesized role of housekeeping genes encoding related mitochondrial proteins, such as succinate dehydrogenases and fumarate hydratase, which act as tumour suppressors in hereditary paragangliomas and uterine fibroids, respectively [18–20].