IL6 and thyroid gland carcinoma: The pooled OR of the limited two studies do not show an increased ratio of IL-6 immunoreactivity in thyroid carcinoma tissues (OR = 1.23 (95% CI 0.62 to 2.43, P = 0.55)) and a large heterogeneity always exists (heterogeneity test, Chi2 = 7.16, P = 0.007, I2 = 86%) (Fig. 3b).