Carbonic anhydrase 9 (CA9) confers resistance to ferroptosis/apoptosis in malignant mesothelioma cells, and inhibition of CA9 promotes mitochondrial fission and autophagy with increased levels of catalytic Fe2+, peroxides, mitochondrial O2−, and lipid peroxidation (55). The gene discussed is CA9; the disease is malignant mesothelioma.