Some evidence from in vitro experiments suggests that HO-1 may be involved in the pathology of HUS: Bitzan et al. demonstrated that HO-1 induction can ameliorate Stx-enhanced heme toxicity in renal epithelial cells [35], while Vareille et al. reported that HO-1 modulates nitric oxide (NO) production in response to STEC in human enterocytes [36]. Here, HMOX1 is linked to hemolytic-uremic syndrome.