Ontology of Biological Attributes id OBA_2055722 (CA13/QDPR protein level ratio in blood) can be described as follows. A compound attribute that is the ratio of amount of carbonic anhydrase 13 (human) in blood to amount of dihydropteridine reductase (human) in blood. Also known as: the ratio of amount of carbonic anhydrase 13 (human) in blood to amount of dihydropteridine reductase (human) in blood.