Given the critical involvement of the endocannabinoid (eCB) system in modulating immune functions, we investigated the potential role of the main elements of such a system, namely type-1 and type-2 cannabinoid receptors (CB1 and CB2), and fatty acid amide hydrolase (FAAH), in distinct immune cell populations of the peripheral blood of AD patients. The gene discussed is FAAH; the disease is Alzheimer disease.