Zhao and colleagues constructed a model combining age, APACHE III, surfactant protein D (SP-D) and interleukin-8 (IL-8) for the prediction of ARDS mortality based on ALVEOLI cohort [7] and the performance in two external cohorts (FACTT and VALID) [27] were comparable to our model. This evidence concerns the gene CXCL8 and acute respiratory distress syndrome.