NDRG2 and lung carcinoma: Immunohistochemistry and immunofluorescence staining of human lung cancer and match normal lung tissue specimens showed that NDRG2 was generally expressed in various normal lung tissues, including bronchial epithelium, smooth muscle, serous gland, and alveolar epithelium [see Fig. 1a (D–I)], while the staining of NDRG2 was weak or negative in SC, AC and SCLC tissues [see Fig. 1a (A–C)].