ANGPT2 and acute respiratory distress syndrome: Only 2 biomarkers, the tissue injury markers ANG2 and procollagen type III N-terminal peptide (P3NP), were higher over the first 7 days in patients with persistent ARDS (ratio of partial pressure of oxygen in arterial blood to the fraction of inspiratory oxygen concentration [PaO2/FIO2] ≤ 200 on day 7) (Figure 7).