GPX4 and COVID-19: The results from using the immune colloidal gold technique show that cytochrome C (Cyt c), cytochrome c oxidase subunit II (COX II), and glutathione peroxidase 4 (GPx4) (panels A, C, and E, respectively) were present in the cytosol outside and inside the mitochondrial outer matrix in a COVID-19 patient versus in a postmortem sample from a control subject (panel B, D, and F, respectively), where the marks of the colloidal gold were inside the mitochondria.