MAPT and Alzheimer disease: Western blotting with TAU-1 antibody, which specifically recognizes tau protein without phosphorylation at several AD-related sites (Ser194, Ser195, Ser198, and Ser202), detected taulower (Fig 1C, TAU-1), whereas antibodies specific to phospho-Ser202, phospho-Thr231, or phospho-Ser396/404 (PHF1) preferentially recognized tauupper (Fig 1C, pSer202, pThr231, and PHF1, respectively).