EGLN2 and breast cancer: FDXR, a mitochondrial flavoprotein, is known to initiate electron transport for cytochrome p450 from NADPH, leading to increased reactive oxygen species (ROS) production (45–47), and acts as a key downstream target gene of the EglN2-NRF1-PGC1α complex, which modulates mitochondrial function and cell proliferation in ER+ breast cancer cells (44).