With regard to the increase in VEGFR-3 lymphatic vessels in the peritumoral tissue, we hypothesized that tumor cells secreting VEGF-C induced the proliferation of peritumoral lymphatic vessels via VEGFR-3, which is located on the lymphatic endothelium, including increasing the diameter and the number of peritumoral lymphatic vessels. The gene discussed is VEGFC; the disease is neoplasm.