Activation of the CXCR1/CXCR2 pathway and the CXCR4/CXCR7 pathway is associated with tumor aggressiveness and poor prognosis; the CXCR3 and CXCR5 axes play a role in tumor suppression; and common variants encoding the CXC chemokine gene have also been studied as biomarkers of CRC [67]. The gene discussed is CXCR4; the disease is neoplasm.