Ontology of Biological Attributes id OBA_2054174 (CD5/CD6 protein level ratio in blood) can be described as follows. A compound attribute that is the ratio of amount of T-cell surface glycoprotein CD5 (human) in blood to level of T-cell differentiation antigen CD6 in blood. Also known as: the ratio of amount of T-cell surface glycoprotein CD5 (human) in blood to level of T-cell differentiation antigen CD6 in blood.