APP and Alzheimer disease: Furthermore, potential ubiquitination enzymes E1s, E2s, E3s, and deubiquitinating enzymes (DUBs) were identified, as well as their contribution to the complex interplay in the AβPP ubiquitination process, illuminating the AβPP ubiquitination, as well as the clearance of iAβ and possible targets for therapeutic approaches in AD [36,37,38,39].