Subsequently, it has been shown that, in transgenic Huntington’s disease mouse models, mutant HTT alters tau phosphorylation (Blum et al., 2015; Gratuze et al., 2015) which is known to be a characteristic of insoluble paired helical filaments that form neurofibrillary tangles (Grundke-Iqbal et al., 1986; Kosik et al., 1986; Wood et al., 1986; Goedert et al., 1988, 1992). Here, HTT is linked to Huntington disease.