FIZZ1 and YM1 expression in the lung is dependent on STAT6 and IL-4Rα. Allergic lung inflammation was induced in RAG2-/-, STAT6xRAG2-/- or IL-4RαxRAG2-/- mice as mentioned in Figure 3 and materials and methods. FIZZ1 and YM1 expression was analyzed in serial sections of mouse lungs by immunohistochemistry. Photomicrographs of FIZZ1 and YM1 expression in epithelial cells (A) and macrophages (B) in representative lung sections are shown. (C) YM1 expression in multinucleate giant cells (MNG) in RAG2-/- mice. Images in (B) and (C) are of 100× magnification.