Though THC shares the ability of AEA and 2-AG to activate both CB1 and CB2 receptors [23], epidemiologic studies have associated cannabis use with lower body mass index (BMI) and lower prevalence of obesity-associated metabolic diseases such as nonalcoholic fatty liver disease (NAFLD) and diabetes compared with non-users [9,10,11,12]. The gene discussed is CNR1; the disease is obesity due to melanocortin 4 receptor deficiency.