CCL2 and neoplasm: Furthermore: (i) manipulation of mutant KRAS expression resulted in parallel changes in Ccl2 expression; (ii) cell culture media conditioned by KRAS-mutant tumour cells featured markedly elevated CCL2 levels compared with media conditioned by KRAS-wild-type tumour cells; and (iii) mice bearing in their pleural space KRAS-mutant tumour cells featured markedly elevated serum CCL2 levels compared with mice harbouring KRAS-wild-type tumour cells (Supplementary Fig. 6d–g).