Intranasal delivery of NEP-EV in a rat model of AD resulted in an increase in expression of B cell leukemia/lymphoma 2 (BCL2), an anti-apoptotic factor, and also a decrease in expression of both IL-1β, an inflammation factor, and BCL2-associated X protein (BAX), a pro-apoptotic factor, in the rat brain, overall improving brain-related behavioural function [153]. Here, BAX is linked to Alzheimer disease.