FBXW2 and lung carcinoma: FBXW2 knockdown in lung cancer cells or Fbxw2 depletion in MEF cells remarkably extended the protein half-lives of both phospho-β-cateninSer552 and total β-catenin (Fig. 3a, b and Supplementary Figure 3a), whereas FBXW2 ectopic expression significantly shortened them, but had no effect on phospho-β-cateninSer33/37 (Fig. 3c and Supplementary Figure 3b).