As panel cell line data is not available for human colon and other cancers, we further analyzed CXCR4 and DR5 expression by RT-qPCR in 7 different cancer cell lines, four of which belongs to colon cancer, and observed an inverse association between CXCR4 and DR5 expression in most of the solid tumor cell lines (Fig. 7C). The gene discussed is CXCR4; the disease is cancer.