DDR1/PVR protein level ratio in blood (Ontology of Biological Attributes identifier OBA_2054072) can be described as follows. A compound attribute that is the ratio of amount of epithelial discoidin domain-containing receptor 1 (human) in blood to amount of poliovirus receptor (human) in blood. Also known as: the ratio of amount of epithelial discoidin domain-containing receptor 1 (human) in blood to amount of poliovirus receptor (human) in blood.