In the immunohistochemical analysis of clinical specimens of thyroid cancer, the expression of EpCAM was detected on the membrane or in the cytoplasm in the differentiated thyroid cancers except one case; however, nuclear expression of EpCAM was significantly detected more frequently in anaplastic cancers compared with differentiated thyroid cancers, which is consistent with the report by Ralhan et al. Our data indicate that both expression levels and localization of EpCAM may be altered during anaplastic transformation from the differentiated thyroid carcinomas. The gene discussed is EPCAM; the disease is anaplastic cancer.