This, in turn, initiates the polarization of RSV-specific T cells to a T2 phenotype so that re-exposure to RSV triggers the expansion of RSV-specific T2 memory cells and the enhanced development of airway hyperresponsiveness (AHR), accompanied by eosinophilic airway inflammation, mucus hyperproduction, and IL-13 release. The gene discussed is IL13; the disease is airway hyperresponsiveness.