CD99L2/RARRES2 protein level ratio in blood (OBA_2053398, an Ontology of Biological Attributes term) can be described as follows. A compound attribute that is the ratio of amount of CD99 antigen-like protein 2 (human) in blood to amount of retinoic acid receptor responder protein 2 (human) in blood. Also known as: the ratio of amount of CD99 antigen-like protein 2 (human) in blood to amount of retinoic acid receptor responder protein 2 (human) in blood.