In a liver metastasis model of CRC, it was observed that cancer cells upregulate the secretion of CXCL1 in TAMs in a VEGF dependent manner, which thereby attracts CXCR2-positive MDSCs to form a pre-metastatic niche in the liver to promote the metastasis of colorectal cancer cells [92]. Here, CXCR2 is linked to cancer.