DPP4 and thyroid gland carcinoma: Univariate cox regression analysis demonstrated that DPP4 [hazard ratio (HR): 0.756, 95% confidence interval (CI): 0.623–0.918, p = 0.004], GPX4 (HR: 0.381, 95% CI: 0.147–0.990, p = 0.048) and GSS (HR: 0.361, 95% CI: 0.139–0.935, p = 0.036) were protective factors for thyroid cancer prognosis (Figure 1G).