VLCFA accumulation, in particular C26:0, has been described in ALD patients in plasma and key tissues such as brain and spinal cord (Igarashi et al., 1976; Moser, 1997; Engelen et al., 2012; Rattay et al., 2020); similar perturbations are also observed in Abcd1 KO mice (Pujol et al., 2004). This evidence concerns the gene ABCD1 and X-linked adrenoleukodystrophy.