KRT19 and lung cancer: The expression of cytokeratin 19 and adhesion molecule CD44v6 mRNA as biomarkers of lung cancer micrometastasis in the late period of surgery were higher than those in the early period in artery-first group (p < 0.05); whereas neither the cytokeratin 19 nor CD44v6 after surgery in the vein-first group exhibited significant change versus those before surgery (p > 0.05).