Contrary to other observations, Amini et al. have reported that CBD, when delivered using chitosan nanoparticles, reduces Aβ plaque formation and learning and memory in AD-bearing rats via enhancing the expression levels of CB1 and CB2, though the effect of empty chitosan NPs on CB1 and CB2 has not been investigated in this study (Amini and Abdolmaleki, 2021). The gene discussed is CNR1; the disease is Alzheimer disease.