Furthermore, using the SOFA score, APACHE II score, and PaO2/FIO2 ratio to separately predict 28-day mortality, we obtained respective AUC values of 0.723 (95% CI 0.580–0.867, P = 0.0059, Fig. 3A), 0.613 (95% CI 0.454–0.772, P = 0.1630, Fig. 3A), and 0.526 (95% CI 0.355–0.698, P = 0.7512, Fig. 3A), suggesting that the predictive ability of serum ATX was higher than that of the typical indicators associated with the severity of ARDS. Here, ENPP2 is linked to acute respiratory distress syndrome.