FSTL3 and pulmonary arterial hypertension: Follistatin-related protein 3 (FSTL3) and Growth/differentiation factor 15 (GDF15) showed high performance not only in discriminating the presence of PAH but also in discriminating FVC%/DLCO% ratio \documentclass[12pt]{minimal}\usepackage{amsmath}\usepackage{wasysym}\usepackage{amsfonts}\usepackage{amssymb}\usepackage{amsbsy}\usepackage{mathrsfs}\usepackage{upgreek}\setlength{\oddsidemargin}{-69pt}\begin{document}$$\ge$$\end{document} 1.6.