GLUL and Alzheimer disease: Oxidized proteins are also present in the MCI hippocampus [38], especially in proteins involved in energy metabolism, synaptic plasticity, and mitogenesis/proliferation, such as α-enolase, glutamine synthetase, pyruvate kinase M2, peptidyl-prolyl cis/trans isomerase 1, hypoxia-inducible factor 1, plasminogen, MYC, tissue plasminogen activator, and BCL2L1, which may play a metabolic role in the progression of MCI to AD.