Thus, suggesting that AQP-4 might exert multiple roles: on the one hand, it is necessary to somehow maintain astrocyte processes in shape, maybe through actin- (Nicchia et al., 2008) or GFAP-mediated mechanisms, as far as both these proteins may be important regulators of structural changes; on the other hand, AQP-4 is necessary to mediate AD efficacy. This evidence concerns the gene AQP4 and Alzheimer disease.