MAPT and Alzheimer disease: OS can upregulate tau phosphorylation in AD through activation of kinases such as GSK3β and mitogen‐activated protein kinases (MAPKs) (Zhu, Castellani, et al. 2001), including JNK, a stress‐activated protein kinase (SAPK) that amplifies stress signals to the nucleus (Zhu, Raina, et al. 2001).