MAPT and tauopathy: To address the role of tau in activating the UPR we have used an in vivo genetic model of tauopathy in Drosophila. Expression of human tau in Drosophila neurons recapitulates many important aspects of human tauopathy, including age-dependent neurodegeneration [13], phosphorylation of tau [14]–[17], formation of actin-rich cytoplasmic inclusions [18], oxidative stress [19], and cell cycle-dependent apoptotic neuronal death [20].