Fig. 1From: Serum concentrations of Krebs von den Lungen-6, surfactant protein D, and matrix metalloproteinase-2 as diagnostic biomarkers in patients with asbestosis and silicosis: a case–control studyComparison of serum concentrations of KL-6, SP-D, and MMP-2, -7, and -9 among the study groups using the Kruskal–Wallis test. a. KL-6. b. SP-D. c. MMP-2. d. MMP-7. e. MMP-9. *P<0.05; **P<0.01Back to article page