STC2 and metastatic malignant neoplasm in the lymph nodes: The dysregulation of STC2 was reported as a major risk factor of EGFR tyrosine kinase inhibitor (TKI) resistance in non-small cell lung cancer (NSCLC) and a predictive marker for lymph node metastasis in esophageal squamous cell carcinoma (Kita et al., 2011; Liu et al., 2019b).