DLL4 and cancer: The DLL4-positive group had a greater depth of tumor invasion (p < 0.01, p < 0.01), more lymph node metastases (p < 0.01, p < 0.05), and significantly more venous (p < 0.05, n.s.)and lymphatic invasion (p < 0.01, p < 0.01 respectively) in not only the cancer cell but also stroma (Table 1, Table 2).