CNTN3/NCS1 protein level ratio in blood (OBA_2053864, an Ontology of Biological Attributes term) can be described as follows. A compound attribute that is the ratio of amount of contactin-3 (human) in blood to amount of neuronal calcium sensor 1 (human) in blood. Also known as: the ratio of amount of contactin-3 (human) in blood to amount of neuronal calcium sensor 1 (human) in blood.