However, under conditions of hypoxia, oxidative stress, or infection (e.g., presence of LPS), the inducible isoform HO‐1 (encoded by heme oxygenase‐1 gene [hmox1]) is upregulated to prevent heme‐induced pathology and ensure efficient iron recycling.70, 71 Importantly, plasma heme and HO‐1 concentrations are raised during both acute72 and subclinical73P. This evidence concerns the gene HMOX1 and infection.