On the other hand, folic acid supplementation in an amyloid precursor protein/presenilin (APP/PSNE1) transgenic mouse model of AD reduced the levels of amyloid beta proteins as this correlated with increased activity of Dnmt1 and the hypermethylation of PSEN1 and APP promoters which correlated with a decrease in their expression [143]. This evidence concerns the gene PSEN1 and Alzheimer disease.