Elevated FVIII has been shown to be an independent risk factor for deep venous thrombosis (DVT) and/or pulmonary embolism (PE).5-10 It has been suggested that increased FVIII levels by itself is insufficient to cause thrombosis; however, increased FVIII with other risk factors could increase the risk of thrombosis.11,12 The mechanism by which an increase in FVIII levels leads to increased thrombogenicity has not been fully understood.8-12 With regard to the previously conducted studies, FVIII level over 1.5 IU/mL is associated with an approximately 5-fold increased risk of venous thrombosis. This evidence concerns the gene F8 and Venous thrombosis.