Moreover, since the SIRT1/PGC1α/Nrf2 pathway appeared to be activated and sustained by 24-OHC, the reduction in the deacetylase SIRT1 expression in the AD brains with the disease worsening points out the importance of preventing the loss of 24-OHC in the brain, which was demonstrated to occur in AD progression [34], in order to maintain the activity of SIRT1-dependent pathways to counteract neurodegeneration. This evidence concerns the gene PPARGC1A and Alzheimer disease.