Coagulation, an ancestral serine protease cascade, exerts a novel function in early immune defense.
Phylogenetically conserved serine protease cascades play an important role in invertebrate and vertebrate immunity. The mammalian coagulation system can be traced back some 400 million years and it shares homology with ancestral serine proteinase cascades involved for instance in Toll receptor signaling in insects and release of antimicrobial peptides during hemolymph clotting. Here we show that b
