The main player of the other branch of UPR, IRE1α, has also been related to p-tau and GSK3β stimulation; phosphorylated IRE1α is found in AD’s patients’ brain, and diminished of IRE1α activity displayed abolition of GSK3β activation, so IRE1α seems to be an essential pathway for its activity [330,331]. This evidence concerns the gene MAPT and Alzheimer disease.