CXCR4 and colorectal cancer: Increased expression of CXCR4 in HT-29/EGFP/FUR cells is in conformity with published data proving that CD133+CXCR4+ cancer stem cells were necessary for tumor metastasis in pancreatic cancer [39] as well as CXCR4 role in oxaliplatin-resistant colorectal cancer cells [5].