By eliciting such effects, radiotherapy has been shown to induce (I) an increase in the production of vascular endothelial growth factor (VEGF) (Park et al, 2001) and fibroblast growth factor (FGF) (Lee et al, 1995), (II) an increase in apoptosis and endothelial cell apoptosis (Garcia-Barros et al, 2003), (III) a decrease in tumour cell density (Peschke et al, 1999), and (IV) a reduction in interstitial fluid pressure (Znati et al, 1996). The gene discussed is VEGFA; the disease is neoplasm.