CYP46A1 and glioblastoma: Based on the findings that CYP46A1 inhibits GBM growth by converting cholesterol to 24OHC, we investigated the effect of efavirenz (EFV) (Fig 6A), which is an anti‐HIV medication known to activate CYP46A1 activity through binding to the enzyme's allosteric site (Mast et al, 2014, 2017a; Anderson et al, 2016).