ATF4 and acute respiratory distress syndrome: To verify whether this triggering of macrophage activation and even hepatocyte apoptosis also occurred in LPS-induced ALI, we administered GSK414, a specific inhibitor of ER stress, in vivo and in vitro, and consistent with previous studies, our results showed that the application of GSK414 effectively suppressed ER stress and subsequent macrophage activation by preventing the activation of the eIF2α/ATF4/CHOP signaling pathway.