The C-X-C motif chemokine ligand 1 (CXCL1) has been implicated in the malignant behavior of solid and hematological neoplasms in combination with the C-X-C motif chemokine receptor 2 (CXCR2), and these two ligands act indirectly on tumor angiogenesis by regulating the trafficking of leukocytes that produce angiogenic factors and a variety of inflammatory cytokines (Mantovani et al., 2010). The gene discussed is XCL1; the disease is neoplasm.