Indeed, it has been shown that ER stress and UPR are induced in human primary skin fibroblast cell lines from X-linked adrenoleukodystrophy patients with ABCD1 mutations and impaired peroxisomal β-oxidation only after incubation with very long-chain fatty acids (van de Beek et al., 2017). Here, ABCD1 is linked to X-linked adrenoleukodystrophy.