found to hydrolyze the endocannabinoids 2-arachidonoylethanolamide and 2-arachidonoylglycerol (two naturally occurring substances that act on cannabinoid receptors on the brain). In other studies, genes were identified on chromosome 1 [22] and 14 [21]. The genes near these linkage peaks, however, have no known effects on cannabis use disorders but deserve further investigation. They include: GPR68 (G-protein coupled receptor 68) which is involved in cAMP regulation and ELTD1 (EGF, latrophilin and seven transmembrane domain containing 1) which encodes a G-protein coupled receptor that is part of the neuropeptide signaling pathway.
