IL6 and thromboangiitis obliterans: In terms of stimuli responsiveness of orbital fibroblasts, our results also showed that no significant differences in the level of IL-6 and IL-8 from IL-1β-treated orbital fibroblasts were observed between TAO and non-TAO patients, although orbital fibroblasts show different capabilities for secreting IL-6 and IL-8 in response to IL-1β depending on the strains of orbital fibroblasts (Figs 1 and 2).