Earlier in vitro studies indicated that both (R,R′)-MNF and (R,S′)-MNF reduce proliferation of 1321N1 astrocytoma, U118MG glioblastoma, and HepG2 hepatocellular carcinoma cells20,27 suggesting that both compounds target GPR55 and β2-AR. This evidence concerns the gene GPR55 and glioblastoma.