The present invention generally provides methods for modulating formation of new blood vessels. In one embodiment, the methods include administering to a mammal an effective amount of granulocyte macrophage-colony stimulating factor (GM-CSF) sufficient to form the new blood vessels. Additionally provided are methods for preventing or reducing the severity of blood vessel damage in a mammal which methods preferably include administering to the mammal an effective amount of GM-CSF. Provided also as part of this invention are pharmaceutical products and kits for inducing formation of new blood vessels in the mammal.