CXCR1 and neoplasm: The IL-8/IL-8R axis plays an important role in such context; tumor cell acquisition of CXCR1 and CXCR2 and/or IL-8 is known to be a common event during tumor progression (29, 32), and, similarly, IL-8 and its receptors are widely expressed by a variety of non-malignant cells present in the tumor microenvironment, including tumor-associated macrophages, neutrophils and endothelial cells (33).