SLIT2 has been implicated in tumor angiogenesis and shown to regulate endothelial migration. SLIT2 was found to suppress endothelial migration in vitro. Loss of SLIT2 resulted in decreased tumor vessel density in a tumor growth mouse model. Loss of endothelial SLIT2 in mouse models of breast and lung cancer suppressed tumor cell migration and metastatic events. The gene discussed is SLIT2; the disease is lung cancer.