SMAD7 and exocrine pancreatic carcinoma: Using a transgenic mouse with pancreas specific Smad7 overexpression, these authors reported that Smad7 blocked TGF-β signaling in the pancreas and induced premalignant ductal lesions with the characteristics of pancreatic intraepithelial neoplasia (PanIN), the precursor stage to pancreatic carcinoma [48].