TG and thyroid gland papillary carcinoma: A study of 1998 patients undergoing surgery for thyroid nodules found an inverse association between peripheral sensitivity to thyroid hormone and papillary thyroid carcinoma, with the OR of 0.18 (95% CI: 0.03–0.96) for each SD increase in the ratio of FT3/FT4, reflecting the potential value of the FT4/FT3 ratio in the diagnosis of thyroid tumors [22].