A compound attribute that is the ratio of amount of proheparin-binding EGF-like growth factor (human) in blood to amount of syndecan-4 (human) in blood. The trait is Ontology of Biological Attributes entry OBA_2053006 (HBEGF/SDC4 protein level ratio in blood). Also known as: the ratio of amount of proheparin-binding EGF-like growth factor (human) in blood to amount of syndecan-4 (human) in blood.