CA9 and cancer: The downregulation of these genes promotes tumor metastasis by stimulating EMT and invasion of cancer cells (BHLHE41); the development of acidosis, which stimulates tumor cell migration (CA9); a decrease in glycolysis; and an increase in oxidative phosphorylation, which promotes metastasis due to a better energy supply (EGLN3, NDUPFA4L2, and ANGPTL4), accelerating the proliferation of metastatic tumor cells (IGFBP3), and improving angiogenesis (VWF).