PLK1 and metastatic malignant neoplasm in the lymph nodes: Remarkably higher expression of PLK1 was observed in all types of cervical cancer patients with lymph node metastasis or CESC patients with lymph node metastasis than in those without lymph node metastasis (X2 = 29.859, P < 0.001; X2 = 29.324, P < 0.001) (Tables 1 and 2).