AGRN and melanoma: To elucidate whether endothelial agrin plays a role in blood vessel recruitment within localized tumors in vivo, we introduced a syngeneic tumor implantation model in which one million firefly luciferase (Luc)-expressing B16F10 melanoma cells derived from C57BL/6 mice were mixed with Matrigel and injected subcutaneously into C57BL/6 mice.