CCL2 and idiopathic pulmonary fibrosis: IPF samples contain significantly more CCL2 and M-CSF than BALF from healthy volunteers, and Ccl2-/- mice are protected from bleomycin-induced pulmonary fibrosis, suggesting that M-CSF contributes to the pathogenesis of IPF through CCL2 production and activation of mononuclear phagocytes [140].