Cancer invasion requires making a path in ECM, so HIFs increase the expression of proteolytic enzymes like cathepsin D, urokinase-type plasminogen activator receptor (uPAR), and matrix metalloproteinase-2 (MMP2) and factors stimulating migration like phosphoglucose isomerase/autocrine-motility factor (PGI/AMF), transforming growth factor-α (TGF-α) and the spreading factor c-Met. The gene discussed is MMP2; the disease is cancer.