IL10 and anemia (phenotype): 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.