GPR18 and neoplasm: GPR18 and 92 are highly expressed by immune cells including macrophages, T- and B-cells, and the primary full agonist N-arachidonoylglycine, NaGly, a metabolite of AEA [51,52], regulates immune functions and cell migration through these receptors [53,54], suggesting that both may contribute to the fine-tuning of the tumor-evoked immune response.