MGAT1 and Alzheimer disease: In this study, an increase in flux through the complex N-glycan synthesis pathway which could be predicted by an increase in the expression of the MGAT1 enzyme by both RNA-seq and qPCR, was corroborated by N-glycomic results showing decreases in high-mannose structures and concomitant increases in complex N-glycans in an independent set of brain tissues, procured from a separate cohort of AD participants vs. controls.