Indeed, decreased O‐glycosylation has been observed in AD patients, its induction is protective in cell and animal models of AD (Zhu, Shan, Yuzwa, & Vocadlo, 2014), and inhibition of a glycoside hydrolase prevented cognitive decline, plaque formation and tau aggregates in transgenic mouse models of neurodegeneration (Hastings et al., 2017; Yuzwa et al., 2014). This evidence concerns the gene MAPT and Mental deterioration.