MAPT and early-onset autosomal dominant Alzheimer disease: Tau is subjected to more than ten types of post-translational modifications (PTMs); under pathological conditions, the coordinated actions of multiple tau PTMs result in its dissociation from microtubules and intra-cellular aggregation to form neurofibrillary tangles (NFTs), a pathological hallmark of Alzheimer’s disease (AD) (for review, see5).