Puisse ́gur et al. described in detail that in A549 lung cancer cells, miR-210 is upregulated by hypoxia-induced HIF-1α; afterward, increased miR-210 represses the electron transport chain via succinate dehydrogenase complex, subunit D (SDHD), and consequent accumulation of succinate inhibits PHD to stabilize HIF-1α, thus forming a positive-autoregulatory loop [167]. The gene discussed is HIF1A; the disease is lung cancer.