The ability of curcumin to augment the antitumor effect of capecitabine in human colorectal cancer by modulating cyclin D1, COX-2, matrix metallopeptidase 9 (MMP-9), VEGF and C-X-C chemokine receptor type 4 (CXCR4), has been assessed by using an orthotopic mouse model [211]. The gene discussed is CXCR4; the disease is colorectal cancer.