In lower concentrations, tumor cell NO promotes tumor growth, neovascularization and invasiveness by induction of p53 mutations, upregulation of vascular endothelial growth factor resulting in neovascularization, increased vascular permeability and vasodilatation (Krischel et al., 1998; Ulibarri et al., 1999; Frank et al., 2000; Luczak et al., 2004; Wai et al., 2006). This evidence concerns the gene TP53 and neoplasm.