The reason why cholesterol-lowering drugs, such as lovastatin, could not protect X-ALD patients from initiation of CALD is probably that the slight reduction in VLCFA and the decrease in cholesterol in peripheral tissues does not affect the cholesterol burden that ABCD1-deficient microglia/macrophages face in the CNS after initiation of demyelination. This evidence concerns the gene ABCD1 and X-linked adrenoleukodystrophy.