Although targeting mitochondrial factors could be a cancer treatment strategy [12,17], as C20orf7 functions as a mitochondrial respiratory factor [18,19,20], how the downregulation of C20orf7 would impact other mitochondrial factors, as well as respiratory complex assembly, and thereby influence the homeostasis of mitochondrial function, has yet to be investigated and clarified. Here, NDUFAF5 is linked to cancer.