COMP/THBS4 protein level ratio in blood (Ontology of Biological Attributes term OBA_2053845) can be described as follows. A compound attribute that is the ratio of amount of cartilage oligomeric matrix protein (human) in blood to amount of thrombospondin-4 (human) in blood. Also known as: the ratio of amount of cartilage oligomeric matrix protein (human) in blood to amount of thrombospondin-4 (human) in blood.