GPX4 and Alzheimer disease: Several studies (Ansari and Scheff, 2010; Cheng et al., 2021; Lill and Freibert, 2020) have observed biochemical and morphological characteristics of ferroptosis in the brains of AD patients or mice, including iron metabolism imbalance, glutathione (GSH) degradation, inactivation of glutathione peroxidase 4 (GPX4) leading to increased reactive oxygen species (ROS), lipid peroxidation, and mitochondrial abnormalities.