To establish profiles of iBK formation, citrated blood or plasma obtained from healthy volunteers or HAE patients in remission was incubated at 37 °C under agitation for up to 2 h, alone or in the presence of one of three standardized stimuli (Figure 1): the particulate material Kontact-APTTTM to activate the contact system, human recombinant KLK-1 to probe the alternate kinin generation pathway, and tPA, known to release iBK in vitro with a slow kinetics [20]. This evidence concerns the gene KLK1 and hereditary angioedema.