The endocannabinoid system comprises the two well characterized Gi/o -protein coupled receptors (cannabinoid receptor 1 (CB1) and CB2), their endogenous lipid ligands, and the enzymes involved in their biosynthesis and biotransformation. Drug discovery efforts relating to the endocannabinoid system have been focused mainly on the two cannabinoid receptors and the two endocannabinoid deactivatin...