AHR and asthma: In addition, we found that lack of dietary AhR ligands during allergen cutaneous sensitization worsened asthma-like airway allergy in a recall phase, a model for ‘atopic march.’ We demonstrated that lack of dietary AhR ligands impacts the inflammatory profile of epidermal cells and increases the production of bioactive TGF-β, causing the retention of Langerhans cells in the skin, in turn leading to exaggerated Th2 responses in the lymph nodes.