Proteins encoded by non-oncogenic adenovirus type 5 and oncogenic adenovirus type 12 differentially affect expression of a number of cellular genes. We have used cDNA micro array analysis to identify a cellular gene that is expressed in Ad12- but not in Ad5-transformed cells. This cellular gene mas found to be the gene encoding follistatin-related protein, a TGF-beta inducible gene, Consistently, a constitutive factor binding to Smad binding elements was found in adenovirus type 12-transformed cells. (C) 2000 Federation of European Biochemical Societies. Published by Elsevier Science B.V. All rights reserved.