NDUFA9 and breast cancer: As shown in Figure 9C, overexpressing MRPL52 increased the protein levels of several mitochondrial respiratory complex components in BC cells exposed to 20% or 1% O2, the effects of which were further abrogated by the mitochondria-specific translation inhibitor, chloramphenicol (CAP), whereas the nuclear-encoded mitochondrial proteins NDUFA9 and ATP5A did not vary.