CLSTN2/SPON1 protein level ratio in blood (OBA_2054895, an Ontology of Biological Attributes entry) can be described as follows. A compound attribute that is the ratio of amount of calsyntenin-2 (human) in blood to amount of spondin-1 (human) in blood. Also known as: the ratio of amount of calsyntenin-2 (human) in blood to amount of spondin-1 (human) in blood.