In malignant mesothelioma under 1% O2 hypoxia, HIF-1 induces Carbonic anhydrase 9 (CA9) expression, which in turn reduces catalytic Fe2+ by downregulating TFRC and upregulating FTL and FTH1 to inhibit erastin-induced ferroptosis [103]. This evidence concerns the gene CA9 and malignant mesothelioma.