CXCR2 and neoplasm: In melanoma, mitogen activated kinase-like protein (MAPK) inhibitor, selumetinib, initiate IL-1β production from macrophages, which promotes secretion of C-X-C Motif Chemokine Receptor 2 (CXCR2) ligands from fibroblasts leading to enhanced tumor growth and dampened therapeutic effect of MAPK inhibitors [235].