HTT and juvenile Huntington disease: Since gliosis is among the most relevant microscopic traits in the neuropathological diagnosis of Huntington’s disease, multiple immunofluorescence experiments were performed, in which specific antibodies against HTT, glial fibrillary acidic protein (GFAP) (astroglia) and Iba1 (microglia) (Supplementary Table 3) were combined for qualitative description.