A major topic of current research has revolved around airway changes in the chronic asthmatic. This process, known as remodeling, is believed to result in irreversible changes in the lung. McMillan and Lloyd induced acute pulmonary eosinophilia and bronchial hyperactivity in mice using multiple allergen challenges. They subsequently induced a chronic phase in a subset of mice using Ova challenge showed significant changes in Ova-challenged mice. Compared with the acutely challenged mice, the Ova group showed deposition of collagen as well as airway smooth muscle and goblet cell hyperplasia. Cytokine profiles in the chronic phase revealed increases of IL-4, transforming growth factor beta 1 (TGF-β1). and IFN-γ. These findings strongly support the concept of airway remodeling and reveal a dual TH1 and TH2 cytokine profile in the chronic phase of asthma.