In AD, the following disturbances are observed: impaired serotonin synthesis, imbalance of the antioxidant system, which involves the signaling pathway MAPK-ERK, SOD-2, GPX1, activation of neuronal apoptosis through caspase-3 and p53 protein (possibly due to oxidative stress), development of an inflammatory reaction in the brain, characterized by the dysfunction of PPARA and PPARG transcription factors. Here, GPX1 is linked to Alzheimer disease.