CXCL1 and neoplasm: As opposed to neutrophil chemoattractants such as CXCL1, CXCL2 (ref. 25), tumour-elaborated CCL2 is a potent monocyte/macrophage mobiliser promoting angiogenesis and metastasis34, 38 and was identified here as the transcriptional target of mutant KRAS in tumour cells.