Effect of the factor V^LEIDEN mutation in the absence and presence of the protein C pathway. Thrombin formation is shown for reactions initiated by 5 pmol/L factor VIIa⋅TF at 6% of the normal plasma concentration of factor VIII in the presence of normal factor V (solid symbols) and factor V^LEIDEN (open symbols) in the absence (circles) or presence of protein C and 1 nmol/L thrombomodulin (squares).