MAPT and Huntington disease: Regarding cellular and animal models of HD, mHtt expression promotes Tau hyperphosphorylation at Ser396 as evidenced in cells in which Tau was co-transfected with mHtt, in contrast to what happens when Tau is co-transfected with wild type Htt in which the levels of phosphorylation are maintained stable (Blum et al., 2015).