Molecular markers of lung injury measured in the blood that are currently used in research, such as soluble receptor for advanced glycation end-products (sRAGE) and surfactant protein D (SP-D), hold potential for use in distinguishing lung injury from cardiogenic edema and prognosticating in ARDS60–62, but they may not distinguish mechanical injury (VILI) from other forms of lung injury or ARDS more broadly. Here, SFTPD is linked to acute respiratory distress syndrome.