Ontology of Biological Attributes identifier OBA_2054722 (EPHB4/EPHB6 protein level ratio in blood) can be described as follows. A compound attribute that is the ratio of amount of ephrin type-B receptor 4 (human) in blood to amount of ephrin type-B receptor 6 (human) in blood. Also known as: the ratio of amount of ephrin type-B receptor 4 (human) in blood to amount of ephrin type-B receptor 6 (human) in blood.