This retrospective cohort study at Maharaj Nakorn Chiang Mai Hospital from 2006 to 2017 assesses the prognostic impact of nodal micrometastasis in resectable pN0 NSCLC patients, using immunohistochemistry staining for cytokeratin AE1/AE3, p53, and BerEp4. The gene discussed is EPCAM; the disease is non-small cell lung carcinoma.