CYP46A1 and early-onset autosomal dominant Alzheimer disease: CYP46A1 activation by EFV was found to increase tissue levels of the biologically active sterol 24HC, the rate of tissue cholesterol turnover [48–50], and mitigate the disease manifestations in mouse models of Alzheimer’s disease, depression, Niemann-Pick disease type C, glioblastoma, and prion disease [48, 49, 51–54].