FN1 and chronic obstructive pulmonary disease: Several lines of studies demonstrated in vitro that ASM cells from COPD patients stimulated with cigarette smoke (CS) extract have higher deposition of collagen type VIII alpha I, but there were no differences in the deposition of collagen V and fibronectin [41, 42]; ASM is the main effector in ARM, which secretes ECM components and, in turn, is functionally responsive to the ECM composition [40].