Angiogenesis, which corresponds to the growth of new blood vessels from pre-existing vessels; is necessary for tumor growth and is an attractive target for anticancer therapy. Since 2004, several antiangiogenic therapies against colon, lung, breast, kidney cancers have been developed and used in clinic.VE-statin/egfl7 was discovered by our team in 2003. It is specifically expressed by endothelial cells during embryonic development and vascular remodelling. Several publications have described the role of VE-statin in vessel formation. VE-statin expression by human tumors has been recently associated with a higher grade and metastatic score and with a poorer prognosis in hepatocellular carcinoma, glioma and colorectal cancer.The aim of my work was to develop tools for the study of the functions of VE-statin in tumor growth and angiogenesis. This analysis allows a better understanding of the mechanisms which modulate tumor progression.