HPCAL1/SERPINB9 protein level ratio in blood (Ontology of Biological Attributes identifier OBA_2053073) can be described as follows. A compound attribute that is the ratio of amount of hippocalcin-like protein 1 (human) in blood to amount of serpin B9 (human) in blood. Also known as: the ratio of amount of hippocalcin-like protein 1 (human) in blood to amount of serpin B9 (human) in blood.