7.1.1.9	cytochrome-c oxidase	HeLa-80 cell	cells proliferate under 80% O2. Under both 20% and 80% O2, mitochondrial reactive oxygen species production is 2fold less in HeLa-80 cells than in wild-type HeLa cells, related to a 2fold higher cytochrome-c oxidase activity. Elevated enzyme activity is associated with a 2fold increase in the regulatory subunit Vb. Treatment with siRNA against subunit Vb lowers its expression, increases mitochondrial generation of reactive oxygen species, decreases enzyme activity by 60-80% and diminishes viability under 80% O2	674791	
7.1.1.9	cytochrome-c oxidase	HeLa-80 cell	elevated COX activity in the oxygen-tolerant HeLa-80 cells, associated with a more than 2fold increase in the regulatory subunit COX Vb, whereas expression levels of other subunits are very close to wild-type HeLa-20 cells	674791