PEX5 and Zellweger syndrome: We also investigated the effect of MIRO1‐mediated motor/pulling forces in cellular models of peroxisome disease.25, 26 Loss of the peroxisomal matrix protein import receptor PEX5 is associated with Zellweger Syndrome, a severe peroxisome biogenesis disorder with several developmental and neurological abnormalities.79 On the cellular level, PEX5‐deficient peroxisomes are import‐incompetent for matrix proteins, with a loss of their metabolic functions.