It is likely that these pathways synergize to increase risk of invasive NTS: in malaria‐infected mice, both exogenous IL‐10 and anemia were required for increased bacteremia64; HO‐1 is induced both by heme and by IL‐10; and the carbon monoxide generated from heme catabolism can induce both HO‐1 and IL‐10.121, 122 Ultimately, it is important to define how these factors may converge to alter neutrophil biology. The gene discussed is HMOX1; the disease is anemia.