GPR55 and encephalopathy, progressive, early-onset, with brain edema and/or leukoencephalopathy: It has been shown that CBD acts as an antagonist on GPR55 and recently, the antagonistic activity of CBD at GPR55 has been suggested as one of the mechanisms for the therapeutic effects of CBD in the treatment of epilepsy, specifically tuberous sclerosis, Dravet syndrome, and Lennox–Gastaut syndrome [18].