ANG and acute respiratory distress syndrome: Signaling was diversely mediated by two secreted Angiopoietin (Ang) family proteins—Ang1 as agonist while Ang2 as context-dependent agonist/antagonist.158 Investigation of circulating biomarkers reveal a correlation between plasma Ang2 levels and severity of acute respiratory distress syndrome (ARDS), while in sepsis studies, Ang2 serves as a biomarker for sepsis severity and is related to sepsis progression.159,160