GPR55 and cancer: To explore whether miR-675-5p exerts its functions through the GPR55-ERK and/or GPR55-RhoA pathways that contribute to cancer proliferation, development and progression [28-31], we examined a number of the main GPR55 signaling downstream target genes, including phosphorylation of extracellular signal regulated kinase (p-ERK), ERK, Cyclin D1 protein (cyclin D1), active form of RhoA (GTP-RhoA), matrix metalloproteinase-2(MMP2), and MMP9.