Hence, IL-17A has been shown in vitro to enhance IL-13 activity by enhancing IL-13-induced signal transducer and activator of transcription 6 (STAT6) activation and augmented airway hyperresponsiveness, mucus production, airway inflammation, and IL-13-induced gene expression in vivo compared with mice given intratracheal IL-13 alone [73]. This evidence concerns the gene IL13 and airway hyperresponsiveness.