These incongruences could be explained by a myriad of differences between our studies including age (adult vs. neonate), strain of the mice (BALB/c vs. C57Bl/6), timing of the exposure to diesel exhaust or EPFR containing PM (post-infection vs. before and during infection), and the type, dose, and route of antioxidant utilized (N-acetylcysteine vs. SOD2). Here, SOD2 is linked to infection.