Given that CISD2 is a redox-sensitive protein localized in mitochondria11,28,29 and the ER12,30, which are two major cellular sources of ROS, and that depletion of CISD2 in lung cancer cells can lead to the accumulation of ROS as shown in our data, it is highly plausible that CISD2 is an antioxidant protein capable of reducing ROS to maintain redox homeostasis in cancer cells. This evidence concerns the gene CISD2 and lung cancer.