Bronchoscopy biopsy pathology results showed poorly differentiated adenocarcinoma in the inner side of the right middle lobe, and immunohistochemistry confirmed the diagnosis of poorly differentiated adenocarcinoma; immunohistochemistry staining results were as follows: CK7 (+), CK20 (−), CDX2 (−), TTF-1 (+), Napsin-A (+), CK5/6 (−), p63 (−), P40 (−), and Ki-67 (80%+) (Fig. 2A–I). The gene discussed is CDX2; the disease is adenocarcinoma.