VD also decreased total tau and phosphorylated tau levels in an okadaic acid-treated AD mouse model and in SH-SY5Y cells with rescued methylated PP2A by increasing the expression of leucine carboxyl methyltransferase 1 and 5,10-methylenetetrahydrofolate reductase (Pan et al., 2021). This evidence concerns the gene MAPT and Alzheimer disease.