MMP9 and pulmonary edema: Our transcriptomic and pathway analyses results suggested direct effects of known or potential NF-κB motif-bearing genes in O3-induced pulmonary edema (e.g., Il6), T cell immunity (e.g., Ccl17, Ccl22, and Il27ra), cardiac mortality and vasoconstriction (e.g., Edn1), extracellular matrix degeneration (e.g., Col1a2 and Mmp9), and interruption of lipid metabolism (e.g., Dbp and Tef) via the TNFR-NF-κB signaling axis.