GPR55 and head and neck squamous cell carcinoma: Nevertheless, in this study, all attempts to block the cytotoxic activity of CAN296 extract by inhibiting CB1, CB2, Gq, GPR55, TRPV1, and TRPV2 failed to reduce the cytotoxicity of CAN296 treatment, suggesting that the mode of action of the extract on HNSCC does not involve these specific receptors.