The relationship between increased F13A1 activity and acute myocardial infarction in young patients was studied, and a possible risk factor for thrombosis was found.27 This corroborates the hypothesis suggested by our research in the sense that there is possibly higher activity of coagulation FXIII in more severe thrombosis as seen in enhanced F13A1 expression. This evidence concerns the gene F13A1 and myocardial infarction.