BECN1 and acute respiratory distress syndrome: In addition, we also examined beclin-1, LC3B (autophagy marker) protein with ARDS patient neutrophils, and the results indicated that autophagy was elevated after the application of anti-PD-L1 antibody (Figures 8C ,D and Supplementary Figure 4), suggesting that anti-PD-L1 antibody might exert a protective effect by increasing the level of autophagy in ARDS.