Because an inverse association between the expression of CD44s and EpCAM along with high expression of CD44v6 were detected in two anaplastic thyroid cancer cell lines, the localization of EpCAM was compared with the expression of CD44s and CD44v6 by immunohistochemistry in 37 clinical specimens of anaplastic thyroid cancers (Table 2). The gene discussed is EPCAM; the disease is thyroid gland undifferentiated (anaplastic) carcinoma.