Although different mechanisms in early and late stages of AD have been reported, highlighting a main role of a reduced glycolytic flux at the onset of the disease (Le Douce et al., 2020), a similar increase in PHGDH level has been also observed in the hippocampus of AD patients, especially in women, as a mechanism to counteract the decrease in Ser enantiomers level observed under AD conditions (Maffioli et al., 2022). Here, PHGDH is linked to Alzheimer disease.