ML-193 (ML193; CID-1261822; CID1261822) is a novel and potent GPR55 (G protein-coupled receptor 55) antagonist with IC50 of 221 nM. Exhibiting >27-, >145- and >145-fold selectivity for GPR55 over CB1, GPR35 and CB2, respectively. CPR55 has been implicated as a novel cannabinoid receptor.