In clinical trials, breast cancer patients treated with long-term EGCG plus radiotherapy for 2–8 weeks showed significantly lower serum levels of vascular endothelial growth factor (VEGF) and hepatocyte growth factor (HGF), as well as reduced activation of metalloproteinase-9 and metalloproteinase-2 (MMP9/MMP2), which are considered promising chemoprophylaxis targets. The gene discussed is MMP2; the disease is breast cancer.