ROS dynamically influence the tumor microenvironment by promoting neoplastic angiogenesis, metastasis and cell survival at moderate concentrations through signalling with MAPK/ERK 1/2 (mitogen-activated proteinkinase/extracellular signal-regulated proteinkinase 1/2), p38, JNK (c-Jun N-terminal kinase) and P13K/Akt (phosphoinositide-3-kinase/protein kinase 3), which in turn activate NF-kB (nuclear factor kappa-light-chain-enhancer of activated B cells), metalloproteases (MMPs) and VEFG (vascular endothelial growth factor). This evidence concerns the gene VEGFA and neoplasm.