CDX2 and medullary thyroid gland carcinoma: In the subgroup analysis based on histologic subtypes, estimated CDX2 expression rates were 0.886 (95% CI 0.837–0.923), 0.882 (95% CI 0.632–0.970), 0.436 (95% CI 0.269–0.618), 0.873 (95% CI 0.756–0.938), and 0.772 (95% CI 0.46–0.944) in adenocarcinoma, mucinous carcinoma, medullary carcinoma, micropapillary carcinoma, and signet ring carcinoma, respectively.