Unlike hemoglobin (Hb)-based O2 delivery biotherapeutics that scavenged NO and therefore triggered significant vascular sequelae, including hypertension, renal dysfunction, and increased risk of myocardial infarction and death [14,15,16], the protein component of OMX-CV is uniquely tuned to bind molecular O2 in a way that reduces NO reactivity 50-fold compared with Hb [13], alleviating the potential risk of vasoconstriction. The gene discussed is GSTM1; the disease is hypertensive disorder.