Figure 2. Detection of NR1I3 in lung tumors induced by 4-(methylnitrosamino)-4-(3-pyridyl)-1-butanone (NNK) in mice. A: Immunohistochemical detection of NR1I3 in lung adenomas and carcinomas. Note that carcinomas showed significantly less NR1I3 expression than did adenomas. B: NR1I3 mRNA expression showed an inverse correlation with tumor size. C: NR1I3 mRNA expression compared between lesions <2 mm and lesions >5 mm. Tumors >5 mm are all carcinomas and lesions <2 mm are all adenomas (Ref. 9). Note that lesions >5 mm expressed significantly less NR1I3 mRNA than did lesions <2 mm. *P<0.05 (unpaired t-test).