In 2012, a related study by Terumoto Koike et al. identified the following four predictors of mediastinal lymph node metastasis: (age ≥ 67 years, CEA ≥ 3.5 ng/ml, tumor size ≥ 2.0 cm, and the CTR ≥ 89%) [26]. The gene discussed is CEACAM5; the disease is neoplasm.