

TheobservationthatabloodclotspontaneouslydissolveswasfirstdescribedbyDenys in1889. Subsequently, thebloodclottingsystemwasshowntobeinvolvedintumor growth. Forexample, asearlyas1925, Fisherreportedthataviantissueexplantstrans- formedtomalignancybyvirusesgeneratedhighlevelsoffibrinolyticactivityundercon-...