All these findings support the hypothesis that cannabinoids might interfere with cancer biology, acting on CB1 and CB2 receptors in a wide range of cancer types, in particular for Δ9-tetrahydrocannabivarin (Δ9-THCV), which is a homologue of Δ9-THC with a propyl side chain instead of a pentyl group. The gene discussed is CNR1; the disease is cancer.