A compound attribute that is the ratio of amount of T-cell surface glycoprotein CD4 (human) in blood to amount of leukocyte immunoglobulin-like receptor subfamily B member 4 (human) in blood. The trait is Ontology of Biological Attributes entry OBA_2054232 (CD4/LILRB4 protein level ratio in blood). Also known as: the ratio of amount of T-cell surface glycoprotein CD4 (human) in blood to amount of leukocyte immunoglobulin-like receptor subfamily B member 4 (human) in blood.