We also looked through references of published manuscripts, editorials, and systematic reviews. The electronic search terms and keywords for obtaining the relevant articles were “MTHFR” OR “MTHFR Polymorphism” OR “MTHFR TT polymorphism” OR “Homocysteine” OR “ischemic stroke in MTHFR TT gene” OR “MTHFR C677T gene in ischemic stroke” OR “MTHFR in stroke.” We fixed the filter so that results were limited to humans and articles published in the English language. This evidence concerns the gene MTHFR and ischemic stroke.