GPR55 and neoplasm: Notwithstanding, further research must explore to what extent the multi-modal, multi-factorial, multi-cellular action of CB1/2 agonists may exert their analgesic effect directly and/or indirectly by regulating the activity of other neuronal or peripheral targets particularly the novel cannabinoid receptor GPR55 (aka CB3), and Transient receptor potential vanilloid 1 (TRPV1), which have been demonstrated to play an important role in the differentiation and death of bone and tumour cells41,71,115–124.