MAPT and Alzheimer disease: Among triplicated genes, both dual specificity tyrosine phosphorylation regulated kinase 1A (DYRK1A) and the regulator of calcineurin 1 (RCAN1) have a well-established role in the aberrant phosphorylation of tau protein, which is one of the main mechanisms underlying the formation of toxic neurofibrillary tangles (NFTs) in AD [48,49].