Ontology of Biological Attributes entry OBA_2054824 (CA5A/KRT18 protein level ratio in blood) can be described as follows. A compound attribute that is the ratio of amount of carbonic anhydrase 5A, mitochondrial (human) in blood to amount of keratin, type I cytoskeletal 18 (human) in blood. Also known as: the ratio of amount of carbonic anhydrase 5A, mitochondrial (human) in blood to amount of keratin, type I cytoskeletal 18 (human) in blood.