The results from these experiments confirmed that pretreatment of HCT-116/OxR cells with CXCR4 inhibitor significantly inhibited the OXA resistance of HCT-116/OxR cells as well as the molecular mechanism by which CXCR4 contributes to OXA resistance of CRC associated with the MAPK- or PI3K/Akt-dependent pathways. The gene discussed is CXCR4; the disease is colorectal carcinoma.