Neutrophils have been reported to support the development of metastases through multiple mechanisms such as the release of proteases that degrade antitumoral factors, the production of leukotrienes that propagate metastasis-initiating cells, the inhibition of antitumor T cell responses [11, 33]. In contrast, tumor growth is inhibited when migration of neutrophils to tumoral areas or granulocyte colony stimulating factors are blocked [34]. This evidence concerns the gene CSF3 and neoplasm.