MTOR and hepatocellular carcinoma: Although lacking classical GPCR characteristics, CXCR7 recruits β-arrestin-2 and signals efficiently through this protein.33,34 Recent studies indicate that CXCR7 may regulate other pathways including epidermal growth factor receptor (EGFR)/extracellular regulated kinase (ERK) axis,30 AKT pathway35 and mTOR signaling.36 To identify pathways which are involved in HCC signal transduction from CXCR7, several selected signaling molecules were examined.