Ontology of Biological Attributes identifier OBA_2053865 (CNTN5/ROBO2 protein level ratio in blood) can be described as follows. A compound attribute that is the ratio of amount of contactin-5 (human) in blood to amount of roundabout homolog 2 (human) in blood. Also known as: the ratio of amount of contactin-5 (human) in blood to amount of roundabout homolog 2 (human) in blood.