SDC4/SERPINE1 protein level ratio in blood (OBA_2055746, an Ontology of Biological Attributes identifier) can be described as follows. A compound attribute that is the ratio of amount of syndecan-4 (human) in blood to amount of plasminogen activator inhibitor 1 (human) in blood. Also known as: the ratio of amount of syndecan-4 (human) in blood to amount of plasminogen activator inhibitor 1 (human) in blood.