VEGFA and neoplasm: VEGF is upregulated by hypoxia (Shweiki et al, 1992), and by overexpression of oncogenes such as mutant ras (Rak et al, 1995) and c-myc (Mezquita et al, 2005) in tumours, and stimulates the migration of endothelial cells, sprouting of blood vessels, and generation of new vessels from existing vasculature in tumours (reviewed in Ferrara, 2004).