Biotech Values

[rfj1862]

VIII is not an obligate component of the coagulation cascade, eg, it can be bypassed (thus FEIBA: Factor Eight Inhibitor Bypassing Activity).

On the other hand thrombin (IIa) is absolutely necessary for coagulation, as is Xa.

Think of it like a tree with coagulation initiators at the top and the coagulation event at the base of the trunk. Inhibiting VIII is like cutting off one of the branches; inhibiting IIa is like cutting down the entire tree.