HIF-1α upregulates the levels of cathepsin D (CTSD), urokinase-type plasminogen-activator receptor (uPAR), and matrix metalloproteinase-2 (MMP2) enzymes, implicated in the basement membrane disruption leading intravasation and dissemination of circulating tumor cells (CTCs) in the organism [45]. The gene discussed is CTSD; the disease is neoplasm.