GAPDH and Alzheimer disease: GAPDH is an enzyme known for its propensity to form aggregates when oxidized or complexed with mutant proteins and the amount of soluble or insoluble GAPDH complexes with Aβ in the CSF from patients with various stages of AD directly correlated with the severity of the disease (Gerszon and Rodacka, 2018; Lazarev et al., 2021).