However, the dual role of HO-1 in tuberculosis may depend on different pathological conditions (Figure 3): On the one hand, HO-1 plays a mainly cytoprotective role in the early stages of the disease, and on the other hand, HO-1 can potentially be cytotoxic due to accumulation of large amounts of heme, and the human host may have an impaired ability to maintain iron homeostasis during the later stages of Mycobacterium tuberculosis infection. Here, HMOX1 is linked to tuberculosis.