Therefore, since IDE alteration seems to contribute to protein misfolding-related diseases and UPS dysfunctionality is a hallmark of the onset and progression of human pathologies, spanning from neurodegenerative and neurodevelopmental disorders to cancer [1,51,52,53], a deeper understanding of the biological significance of IDE–proteasome interaction and of the factors that can affect this interaction is mandatory. Here, IDE is linked to neurodevelopmental disorder.