CYP46A1 and Alzheimer disease: Compared with control mice, the amounts of CYP46A1 protein and 24-S-hydroxycholesterol in the hippocampus was lower in THY-Tau22 mice, a model of AD-like Tau pathology without amyloid pathology (Burlot et al., 2015), indicating that AD may decrease the expression and activity of CYP46A1.