HMOX1 and acute respiratory distress syndrome: The transcript expression of the pro-inflammatory (IL8, IL6 and TNF, Figure 4a–c) and oxidative stress markers (GSTA1, HMOX1 and SOD3, Figure 4d–f) were assayed in the bro-ALI models at 24 h, 48 h and 72 h post-exposure to sham and aerosolized DEP.