Bmp4 expression is increased in epimorphin-transfected myofibroblasts. pCEN- and EpiS-transfected MIC 216 cell lines were grown for 7 days either alone (a) or with endoderm (+E) (b) and harvested. Total RNA was prepared and Northern blot hybridization analysis was performed using a 32P-radiolabeled full-length Bmp4 cDNA probe or a radiolabeled 18S rRNA probe for normalization. (c)Bands specific for Bmp4 mRNA or 18S were quantified as indicated in Methods and Bmp4 expression levels were determined.