To investigate the expression of E-cadherin as a tumour suppressor in various thyroid cancer types, we measured the expression of E-cadherin protein in human papillary thyroid cancer cells (TPC: TPC1, SNU373 and SNU790), anaplastic thyroid cancer cells (ATC: 8505C and CAL62) and follicular thyroid cancer cells (FTC: FTC133) by Western blot. Here, CDH1 is linked to thyroid gland undifferentiated (anaplastic) carcinoma.