CNR1 and central nervous system cancer: Further evidence of crosstalk between oncogenic signalling pathways and either CB1R or CB2R is highlighted by the observation that ∆9-THC, WIN-55,212-2 or JWH-133, can downregulate the vascular endothelial growth factor receptors (VEGFRs), to reduce the angiogenesis and metastasis of skin cancer cells in vivo [99], and of glioma cells in vitro and in vivo [100] (Figure 2).