AGR2 and thyroid gland undifferentiated (anaplastic) carcinoma: While AGR2 expression was weak or absent in our normal thyroid, a moderate to strong AGR2 staining was observed in 46% of adenomas, 52.8% of follicular carcinomas, 81.8% of papillary carcinomas, and 31.6% of anaplastic carcinomas of the thyroid.