The cells showed positivity for thyroid cell marker transcription factor molecule PAX-8 and cytokeratin 18, however, they were negative to differentiated thyroid tumor markers such as thyroglobulin and thyroid transcription factor-1 (TTF-1) which is in good accordance with previous observations in other ATC cell lines [41, 43, 44]. This evidence concerns the gene NKX2-1 and thyroid tumor.