The overexpression of NADH dehydrogenase (ubiquinone) 1 alpha subcomplex 4-like 2 (NDUFA4L2) promotes mitochondrial relocalization of HER2 and inhibits the production of ROS, thus making HER2-positive breast cancer cells more resistant to herceptin treatment [141]. The gene discussed is COXFA4L2; the disease is breast cancer.