Decreased plasmalogen levels and increased VLCFA levels in MS patients and animal models of MS (Yanagihara and Cumings, 1969; Singh et al., 2004; Senanayake et al., 2015).Decreased PMP70 protein levels (Gray et al., 2014) and suppressed PEX3 and PEX5L transcripts in brain tissue from MS patients (Roczkowsky et al., 2022).Suppressed Abcd1, Cat and Pex5L mRNA transcript levels and decreased catalase protein levels in brain tissue of cuprizone-exposed mice (Roczkowsky et al., 2022); decreased catalase and DHAP-AT levels in spinal cord of EAE mice (Singh et al., 2004). The gene discussed is PEX5L; the disease is myeloid sarcoma.