The upregulated VEGF-C and VEGF-D further induce the opening of VEGF channels and the binding of surface substances of lymphocytes. The increased permeability of lymphatic vessels is convenient for cancer cells to invade lymphatic vessels and achieve lymphatic diffusion [17–19]. Therefore, VEGF can promote lymphangiogenesis and promote lymphatic metastasis of tumors. The gene discussed is VEGFD; the disease is cancer.