POU5F1 and thyroid gland papillary carcinoma: Anaplastic, follicular and papillary thyroid cancers presented high expression of stemness-related genes, such as POU class 5 homeobox 1 (OCT4), nanog homeobox (NANOG), ATP-binding cassette subfamily G member 2 (ABCG2) and stage-specific embryonic antigen 1 (SSEA-1), when compared to benign lesions and normal thyroid, which were enhanced by Fluorouracil treatment, indicating their possible additional role in tumor chemoresistance [38].