TGFB1 and adenoma: Because we also observed frequent mutations in TGF-β signaling pathways in adenomas, we sought to determine a potential association between the expression levels of CEA and members of the TGF-β signaling pathway including TGFBR1, TGFBR2 and Smads adaptor β2SP in 26 early adenomas and 10 normal colon tissues (Fig 3C).