We found that the PERK inhibitor induced a more premature cell death in X-ALD than control fibroblasts following 48 h with 2 μg/mL TM (25% for X-ALD and 12% for controls), while GSK2606414 alone did not have any effect on cell death (Supplemental Fig. S4). This evidence concerns the gene EIF2AK3 and X-linked adrenoleukodystrophy.