HMOX1: gene encoding a stress-sensitive enzyme involved in heme catabolism. Although the link between sickle cell anemia and resistance to malaria is well established, the underlying molecular mechanisms are still mysterious. It was thought that the protective effect was based on a reduction in the parasite load. In fact, it seems that this HMOX1 enzyme is more abundant in individuals with sickle cell disease: antioxidant molecules are produced in greater quantities, which could prevent the serious symptoms of malaria and allow a certain tolerance to this disease.