CXCR2 and neoplasm: The baseline and radiation-enhanced secretion of CXCL8 (and its orthologues CXCL1, CXCL2 and CXCL5) from PTEN-deficient prostate tumour epithelial cells exerts both autocrine and paracrine actions within the tumour microenvironment given the expression of CXCR1 and CXCR2 upon multiple cell types (33,34).