MCAM/NTRK3 protein level ratio in blood (OBA_2053790, an Ontology of Biological Attributes identifier) can be described as follows. A compound attribute that is the ratio of amount of cell surface glycoprotein MUC18 (human) in blood to amount of NT-3 growth factor receptor (human) in blood. Also known as: the ratio of amount of cell surface glycoprotein MUC18 (human) in blood to amount of NT-3 growth factor receptor (human) in blood.