Although this study has focused on lung ADC in terms of the oncogenic role of the CISD2–ROS–EGR1/GPX3 axis, we found that CISD2 expression was also upregulated and seemed to be inversely correlated with prognosis among patients with lung SQC (unpublished data), another major lung cancer subtype that is etiologically and genetically distinct from lung ADC. Here, GPX3 is linked to lung cancer.