The present invention relates to nucleic acid molecules comprising certain truncated forms of the human cytomegalovirus (CMV) immediate-early enhancer-promoter, either alone or operably linked to transgenes of interest, including those encoding partially-deleted CFTR proteins. This invention further relates to vectors comprising these nucleic acid molecules and host cells transformed by such vectors. The nucleic acid molecules, vectors and transformed host cells of the present invention are useful for treating a variety of genetic, metabolic and acquired diseases, including inter alia cystic fibrosis (CF) airway disease.