The imbalance between increased ERα and decreased ERβ was found in multiple kinds of TC cells, such as thyroid medullary cancer cell lines (TT), anaplastic thyroid cancer (ACT) cell lines (ARO), and papillary thyroid carcinoma (PTC) cell lines (KAT5), which may alter cell behavior (8, 9). This evidence concerns the gene ESR2 and thyroid gland papillary carcinoma.