CNR2 and Alzheimer disease: Analysis of mRNA levels from both cannabinoid receptors by qRT-PCR showed that CNR2 expression was significantly increased in AD patients (5.567 ± 1.422) compared to controls whereas CNR1 levels were 50% decreased (0.525 ± 0.155) (Fig. 6b), indicating that the ECS is deregulated in AD, as described before [20].