In particular, the inactivation of the heme-degrading enzyme heme oxygenase-1 (HMOX1) is lethal in the context of hereditary leiomyomatosis and renal-cell cancer (HLRCC), a form of tumor characterized by germline mutations in the gene encoding for the enzyme fumarate hydratase (6). This evidence concerns the gene HMOX1 and hereditary leiomyomatosis and renal cell cancer.