A compound attribute that is the ratio of amount of T-cell surface glycoprotein CD5 (human) in blood to amount of pro-interleukin-16 (human) in blood. The trait is CD5/IL16 protein level ratio in blood (OBA_2054175, an Ontology of Biological Attributes entry). Also known as: the ratio of amount of T-cell surface glycoprotein CD5 (human) in blood to amount of pro-interleukin-16 (human) in blood.