While past studies utilized immunohistochemistry in determining CXCR4 protein expression in human CRC, we combined proteomic and transcriptomic approaches of Western blotting and RT-PCR with 5mC combined bisulfite restriction analysis (COBRA) [53] to measure CXCR4 protein and mRNA expression along with promoter methylation status in CRC tumors. Here, CXCR4 is linked to colorectal carcinoma.