Importantly, we made novel findings that BaP-activated AhR can bind to the promoter region of RhoA and regulate RhoA/Rho-kinase activation, and inhibition of RhoA significantly suppresses co-exposure-induced AHR, Th2-associated airway inflammation, and TGFβ1 signaling in a mouse model of asthma. This evidence concerns the gene AHR and inflammation.