The incidence of thyroid cancer (TC) has continuously risen worldwide in the past three decades. While most TC patients have a good prognosis, 60% of them still suffer from lymph node metastasis, which is significantly associated with patient prognosis.1 Circular RNAs (circRNAs) are a large class of noncoding RNAs that function as tumor suppressors or tumor promoters in multiple human cancers, including TC.2 In the previous study, we found one circRNA (circSSU72) was significantly up-regulated in both tissues and cell lines of papillary thyroid carcinoma.3 However, the biological role and associated mechanisms of circSSU72 in TC, especially in the field of metastasis, have not been well elucidated.