Dysfunctions of the ubiquitin-proteasome system were found in both ABCD1 null mouse model spinal cords and X-ALD fibroblasts, which speculated that oxidative stress and inflammation stimulated an increase in oxidized proteins that needed to be ubiquitinated, consequently, resulting in the inhibition of proteasome activity because of massive accumulation of polyubiquitinated proteins (104). Here, ABCD1 is linked to adrenoleukodystrophy.