IL33 and squamous cell carcinoma: To determine the relation between clinical and pathological parameters and the IL-33 expression in adenocarcinoma and squamous cell carcinoma tissues, we then divided the 48 adenocarcinoma and 22 squamous cell carcinoma tissues into 3 subgroups according to the intensity of IL-33 immunohistochemistry staining, i.e., high expression (++, intensity score:5–7), low expression (+, intensity score: 2–4) and negative expression (-, intensity score:0–1) subgroups.