It is also conceivable that the impact of homocysteine on hemorrhagic stroke outcomes is moderated by factors such as the extent of hematoma expansion, the presence of intraventricular hemorrhage, or patient-specific responses to hyperhomocysteinemia, such as variations in the methylenetetrahydrofolate reductase gene, which could influence individual susceptibility to the detrimental effects of high homocysteine levels (21–23). The gene discussed is MTHFR; the disease is hemorrhagic stroke.