A compound attribute that is the ratio of amount of syndecan-4 (human) in blood to amount of P-selectin (human) in blood. The trait is Ontology of Biological Attributes id OBA_2055744 (SDC4/SELP protein level ratio in blood). Also known as: the ratio of amount of syndecan-4 (human) in blood to amount of P-selectin (human) in blood.