CSF2 and neoplasm: Surface transplants revealed an accelerated and enhanced angiogenic response of GM-CSF overexpressing cell lines compared with GM-CSF negative clones (Fig. 2B–D), leading to a fourfold (42 days) higher amount of blood vessels within the tumor tissue (Fig. 2C) and fivefold (14 days) or twofold (21 days) higher amount of blood vessels in the tumor adjacent stroma (Fig. 2D).