A compound attribute that is the ratio of amount of CD166 antigen (human) in blood to amount of contactin-1 (human) in blood. The trait is ALCAM/CNTN1 protein level ratio in blood (OBA_2054292, an Ontology of Biological Attributes term). Also known as: the ratio of amount of CD166 antigen (human) in blood to amount of contactin-1 (human) in blood.