TCGA database indicated that among several ligands, CXCL1, CXCL3, CXCL5, CXCL7 and CXCL8 (ligands for CXCR2) and CCL15 (ligand for CCR1) were particularly upregulated in CRC tissues compared with other cancers (Fig. 1a and Supplementary Fig. 1a). The gene discussed is CXCL3; the disease is colorectal carcinoma.