NGLY1 and Global developmental delay: Moreover, no abnormalities in the protein level of ER stress markers and NFE2L1-regulated proteasome subunits and deubiquitinating enzymes were observed by the Suzuki group in the brains of the Ngly1−/− rats discussed in Section 3.1, even though these animals showed developmental delay, movement disorder, and neurological symptoms similar to NGLY1-deficient patients [46].