MUC1 and combined pulmonary fibrosis-emphysema syndrome: Recently, Chiba et al.demonstrated that two biomarkers of fibrosis, namely KL-6 and surfactant protein D,are good indicators of the extent of fibrosis in patients with CPFE.(38) High KL-6 and surfactant protein D levels were found to correlatenegatively with all lung volumes and with DLCO.(38) Kishaba et al. demonstrated that high levels of KL-6 are predictors ofacute exacerbations in patients with CPFE.(10)