Thus, the genetic studies of MTHFR and stroke in China and CSPPT trial of folic acid for stroke prevention in China both demonstrated a protective effect of folic acid for stroke prevention.13, 14, 15 After stratification of all large trials of folic acid (>1000 participants) in a meta-analysis of trials, we showed that trials of folic acid conducted in China reduced the risk of stroke, but those in Western populations had no beneficial effects for stroke prevention. The gene discussed is MTHFR; the disease is Stroke.