Kallikrein (EC 3.4.21.8) specifies those serine proteinases which liberate kinins from kininogens by limited proteolysis and have no or only little proteolytic activity on other proteins (for review, see refs. 2,3,21). Unfortunately, this definition fits two totally different groups of proteinases: the glandular, tissue or organ kallikreins on the one hand, and the plasma or serum kallikrein on...