CXCR2 and colorectal carcinoma: The CXCL1–CXCR2 axis is also important for the formation of the pre-metastatic niche of CRC liver metastasis, and TSU68, an anti-angiogenic receptor tyrosine kinase inhibitor, suppressed CXCL1 expression in the pre-metastatic liver, resulting in suppression of the homing of CXCR2+ neutrophils and subsequent liver metastasis in a mouse model [20].