This duality highlights the complex role of EVs: while they may provide neuroprotection by facilitating the secretion of APP and neurotoxic metabolites in the early stages of AD, they can also become sites for the generation and accumulation of APP metabolites in later stages, particularly when endosomal-lysosomal degradation systems are compromised (Pérez-González et al., 2020). Here, APP is linked to Alzheimer disease.