TAFAZZIN and Zellweger syndrome: Unlike other diseases like Zellweger syndrome (Heymans et al, 1983) and RCDP (Dorninger et al, 2015) characterized with their plasmalogen loss caused by an upstream defect associated with integrity of functional peroxisomes (Wanders & Brites, 2010), the observed absence of change in the plasmenylethanolamine level in the TAZ-KD heart despite the large loss of plasmenylcholine (Fig 2A and B) implies the absence of peroxisome deficiency for synthesizing plasmalogen precursors (Fig S2 and Appendix 1, Supplementary Text 1) (Kimura et al, 2018).