MMP2 and idiopathic pulmonary fibrosis: Concentrations of eight IPF-related biomarkers (eotaxin, Flt-3L, interleukin-8, macrophage-derived chemokine, monocyte chemoattractant protein 1, and matrix metalloproteinase 2/7/9 [MMP-2/7/9]) were measured, standardized, and summed to generate a multibiomarker score.