Oxidative damage has been shown to occur before disease onset in a mouse model of ALD [51], and is believed to underlie axonal degeneration, since treatment with antioxidants could counteract this damage [52] as well as reverse locomotor impairment in mice deficient in both ABCD1 and ABCD2 [53]. The gene discussed is ABCD1; the disease is X-linked adrenoleukodystrophy.