CD9 expression tended to increase in patients with smaller tumor size (OR 0.83, 95% CI 0.44–1.55, p = 0.554), lower tumor grade and stage (OR 0.50, 95% CI 0.16–1.60, p = 0.244; OR 0.56, 95% CI 0.27–1.16, p = 0.120), and absent lymph node metastasis (OR 0.68, 95% CI 0.41–1.13, p = 0.137); however, this increase was not statistically significant (Table 4, Additional file 1: Figures S1–S7). The gene discussed is CD9; the disease is metastatic malignant neoplasm in the lymph nodes.