CNR1 and neoplasm: Since the discovery of the link between CB1 receptor and osteoclastic bone resorption in 200540, numerous studies have reported that osteoclasts, osteoblasts, immune, tumour and peripheral neurons in the skeleton express CB1 and CB2 receptors, and both genetic and pharmacological modulation of these receptors exerted paradoxical effects on bone cell activity and skeletal remodelling32–39.