B4GALNT1 and Huntington disease: This treatment only partially depletes gangliosides and thus mimics the partial reduction of gangliosides that is observed in HD (36, 64) and other pathophysiological conditions (65–67); (ii) N2a cells overexpressing an N-terminal (exon 1) fragment of mHTT (N2a 97Q cells), an HD model that recapitulates the decrease in GM1 cellular levels described in other HD models and patients’ cells (39, 40); (iii) knockout (KO) of B4galnt1 in N2a cells by CRISPR-Cas9 (68), to block the synthesis of complex gangliosides (Fig. 3A) and model a defect of ganglioside biosynthesis in humans (41, 42).