Increased intratumor hypoxia induces the selection of more invasive metastatic clones of the cancer cells that are resistant to anti-angiogenic agents [37], through the production of pro-migratory proteins, such as stromal cell derived factor 1 alpha (SDF1-α) and hepatocyte growth factor- scatter factor (HGF-SF) and pro-invasive extracellular matrix proteins [38, 39]. The gene discussed is HGF; the disease is cancer.