PGK1 and Alzheimer disease: The other enzymes, TPI, glyceraldehyde-3-phosphate dehydrogenase (GAPDH), phosphoglycerate kinase (PGK1), PGAM1, ENO1, and ENO2, were all decreased in one or more non-AD group compared to either MCI-AD or DEM-AD (adjusted p-value < 0.1; Fig. 5).