Kolbe et al. (2021) recently presented the effects of Δ9-THC in glioblastoma multiforme (GBM) and the ability to modify the number of Ki67+ cells of human patient-derived GBM cells, particularly through the activation of the orphan receptor GPR55 without affecting CB1R and CB2R as usual targets. The gene discussed is CNR1; the disease is glioblastoma.