MAPT and tauopathy: In contrast, Tau (high); xbp-1s Tg; atf-6 (−/−) animals accumulated total tau protein similar to the level seen in Tau (high) animals (Fig. 4c, d; Supplementary Fig. 7b), indicating functional ATF-6 is necessary for xbp-1s-mediated tauopathy detoxification.