APOE and X-linked adrenoleukodystrophy: Notably, oxysterols are strong activators of LXR, which induces the transcription of target genes involved in cholesterol export, such as ABCA1 and APOE [69], as well as the acyl-CoA desaturase SCD1, probably also contributing to our finding of increased levels of monounsaturated CE-FAs in X-ALD.