To understand whether AhR solely expressed by T cells is sufficient to regulate ozone induced lung inflammation, AhR-deficient mice in T lymphocytes (AhRCD4cre) were generated by crossing AhRflox/flox with CD4cre mice (WTCD4cre), and T cell-specific AhR depletion was checked in these mice (Supplemental Figure 4). This evidence concerns the gene AHR and inflammation.