SFTPD and acute respiratory distress syndrome: Previous studies suggested that multiple plasma biomarkers, such as IL-6, IL-8, angiopoietin-2 (ANG-2), Kerbs von Lungren 6 antigen (KL-6), receptor for advanced glycation endproducts (RAGEs), and surfactant protein D (SP-D), had a predictive value for ARDS prognosis [1–4].