Chu reported that CK-19 is strongly expressed in cellular membrane of over 70% of papillary thyroid carcinomas [35], and this positivity is also seen in metastatic cells within the lymph node; CK-19 is not present in other elements of the lymph node, thus CK-19 is eligible as a marker of metastasis of PTC. Here, KRT19 is linked to differentiated thyroid carcinoma.