Based on the aforementioned evidence, anaemia – in the absence ofpathology related impairments in vasodilatory signalling31 – may lead to a steepening of CO2 CVR due to a reduction inhaemoglobin (Hb)-mediated nitric oxide (NO) scavenging.26,27,32 Given the complex roles ofNO33, , –36 and cerebral acid-basebalance4, , , , –9 in cerebrovascular regulationwe quantified blood-borne markers of NO uptake/release, cerebral metabolism, andcerebral CO2 washout to provide insight into the influence of anaemia onCVR. The gene discussed is GSTM1; the disease is anemia (phenotype).