IL4Ra is critical for inflammation-induced neck cell expansion and metaplasia development. (A) H&E corpus sections from healthy 4-month-old BALB/c (left), TxA23 (center), and TxA23×Il4ra-/- (right). Enlarged inlay section shown in top left corner. Scale bars: 200 μm. (B) Immunofluorescent staining with anti-GKN3 (red), GSII (green), and Hoechst (blue) showing SPEM development (GKN3+GSII+, yellow) in BALB/c mice (left) and 4-month-old TxA23 (center) and TxA23×Il4ra-/- mice (right). Scale bars: 50 μm. (C) Disease scores of 4-month-old TxA23 and TxA23×Il4ra-/- mice. Each dot represents 1 mouse (N = 9). Significance was determined using a Mann–Whitney U test. ∗∗∗P = 0.001 ∗∗∗∗P <0.0001. (D) Quantification of SPEM+ (GKN3+) glands in 4-month-old TxA23 and TxA23×Il4ra-/-. Each dot represents 1 mouse (N = 9–15). Significance was determined using a Student t test. ∗∗∗P <0.0001. Data show means ± SEM.