Patients with a lower PTEN-Δ expression (PTEN-Δ ≤ median expression value) showed a significantly higher rate of lymph node metastasis than patients with a higher PTEN-Δ expression (PTEN-Δ > median expression value) (Fig. 2a, p = 0.024). Here, PTEN is linked to metastatic malignant neoplasm in the lymph nodes.