MTHFD2 and Alzheimer disease: Notably, reactions associated with the folate metabolism (MTHFDm, MTHFDm2, MTHFCm, MTHFD, MTHFD2) were also associated with genes differently expressed in AD, in particular with low-expression of gene MTHFD1 and high-expression of gene MTHFD2 (Fig. 5, Table S09).