Objective: Papillary thyroid cancer (PTC) is the most common endocrine malignancy worldwide.Increased incurability of PTC is strongly correlated with its high recurrence and metastasis rate.Despite recent progress in identification of genetic or epigenetic alterations of signaling pathway, the molecular basis for metastasis remains unclear.Toll-like receptors (TLRs), which have been implicated in the development of innate immune responses against microbial infection, are reported involved in the progression and metastasis in various cancers.However, little is known about the expression of TLRs and their functions in thyroid cancer.