blood protein measurement blood plasminogen activator inhibitor 1 level 2019-02-15T10:09:09Z CMO:0003034 EFO:0004792 a measurement of the amount of plasminogen activator inhibitor 1 (PAI-1)in the blood. PAI-1 is a serine protease inhibitor protein that functions as the principal inhibitor of tissue plasminogen activator (tPA) and urokinase (uPA), the activators of plasminogen and hence fibrinolysis (the physiological breakdown of blood clots). clinical_measurement_ontology plasminogen activator inhibitor 1 measurement sjwang