The transgene contains the promoter, first intron and 5' untranslated region of the human keratin 18 gene and the 34-bp alpha mosaic virus transcriptional enhancerdriving the expression of a beta-galactosidase gene that contains an SV40 large T antigen nuclear localization signal. X-gal staining analysis indicated that expression occurs in the airway epithelium of transgenic mice. (J:94886)