CYP39A1 and Parkinson disease: Importantly, all four P450 genes, CYP7B1, CYP46A1, CYP39A1 and CYP27A1 are expressed in iPSC-derived neurons at day 65 from the FOUNDIN-PD cohort with strongest expression of CYP46A1 and CYP27A1 (Figure 3).