Furthermore, gene-therapeutic delivery of CYP46A1 into the striatum of HD affected mice not only improves disease pathology and reduces mutant HTT aggregates, but also enhances cholesterol metabolism by upregulating the expression of cholesterogenic enzymes and ApoE (Boussicault et al., 2016; Kacher et al., 2019, 2022). Here, APOE is linked to Huntington disease.