KRT19 and metastatic malignant neoplasm in the lymph nodes: A hypothetical limitation of the study is the inability of OSNA to detect other biomarkers besides CK19, but several studies have demonstrated that CK19 mRNA is the best performing single marker for detecting lymph node metastasis in breast, lung, colorectal, prostate, cervical, and gastric cancers [23,24,25,26,27,28,29].