APOA1 and thyroid cancer: It visualized the effect measure of each exposure factor on outcome and estimated 95% confidence interval (CI) of individual studies, and it revealed that the concentration of “total cholesterol” (p = 0.01, OR = 0.281, 95% CI: 0.107–0.736), “HDL cholesterol” (p = 0.004, OR = 2.530, 95% CI: 1.347–4.750), “apolipoprotein B” (p = 0.007, OR = 0.013, 95% CI: 0.001–0.299), and “ratio of apolipoprotein B to apolipoprotein A1” (p = 0.017, OR = 0.365, 95% CI: 0.159–0.838), respectively, was causally correlated with thyroid cancer.