The correlation between increased level of COHb and the risk of LOS development can be explained by the association between an increased level of COHb and oxidative stress [3–5], since an increase of HO induction and activity (and consequently an increased synthesis of CO) represents a response to oxidative stress [19] which is involved in detrimental pathways activated during neonatal sepsis [20]. The gene discussed is HMOX1; the disease is Neonatal sepsis.