TP53 and Alzheimer disease: 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.