CXCR1 and neoplasm: As a multifunctional proinflammatory chemokine, CXCL8 is significantly upregulated in both the tumor and tumor-derived microenvironment and acts as a key regulator of proliferation, migration, angiogenesis, metastasis, and resistance to chemotherapeutics through binding with the high-affinity CXCR1 and CXCR2 G-protein–coupled receptors (Lee et al., 2013).