Here, we generated an asthma mouse model with RhoA–conditional KO mice (Sftpc-cre;RhoAfl/fl) in type II alveolar epithelial cells (AT2) and demonstrated that AT2 cell–specific deletion of RhoA leads to exacerbation of allergen-induced airway hyperresponsiveness and airway inflammation with elevated Th2 cytokines in bronchoalveolar lavage fluid (BALF). This evidence concerns the gene RHOA and asthma.