Binary logistic regression analysis showed that the expression levels of circRNA-000121 and hsa_circRNA_004183 in the peripheral blood (Table 4) as well as the expression levels of hsa_circRNA_000121, hsa_circRNA_004183, hsa-miR-4763, hsa-miR-6775, SRC, and MMP-14 in PTMC tumor tissues (Table 5) were not associated with PTMC lymph node metastasis. This evidence concerns the gene MMP14 and neoplasm.