SPP1 and idiopathic pulmonary fibrosis: A recent study focusing on biomarkers that might assist in distinguishing IPF from non-IPF-ILDs have identify in the plasma of 149 IPF patients (derivation cohort n = 86, validation cohort n = 63) that a biomarker index composed of SP-D, MMP-7 and osteopontin enhanced diagnostic accuracy for IPF compared to other ILDs (rheumatoid arthritis associated ILD (n = 33); alternative idiopathic ILD (n = 41)) [61].