Recently, we showed that the constitutive TRα1 overexpression in the intestinal epithelium (vil-TRα1 mice) allows increased cell proliferation and adenoma development; this overexpression also enhances the intestinal tumorigenic process in an Apc mutated genetic background (vil-TRα1/Apc+/1638N mice) [9]. This evidence concerns the gene APC and adenoma.