Numerous investigations have demonstrated a significantly higher incidence of thyroid cancer in women compared to men and the previously reported presence of estrogen receptor in thyroid glands (Miki et al., 1990; Lewy-Trenda, 2002) suggests that estrogen plays an important role in development and progression of thyroid neoplasms due to the effect of sex hormones (Rahbari, Zhang & Kebebew, 2010). Here, ESR1 is linked to thyroid cancer.