CSF1 and chronic obstructive pulmonary disease: Cytokine M-CSF and IL-8 were seen at higher levels in COPDchips compared to the healthy cells. The fact that M-CSF was exclusivelyup-regulated in the presence of the viral mimic PolyI:C suggestedthat it may serve as a novel biomarker for acute viral exacerbationin COPD patients.