Our research results indicate that thyroid cancer is correlated with decreased circulating TNF levels (IVW-OR: 0.96, 95% CI 0.93–0.99, p = 0.009) and IFN-γ (IVW-OR: 0.97, 95% CI 0.94–1.00, p = 0.046), as well as a suggestive association with increased circulating leukemia inhibitory factor receptor (LIFR) levels (IVW-OR: 1.03, 95% CI 1.01–1.06, p = 0.020). This evidence concerns the gene IFNG and thyroid cancer.