A compound attribute that is the ratio of amount of adenine phosphoribosyltransferase (human) in blood to amount of proteasome activator complex subunit 1 (human) in blood. The trait is APRT/PSME1 protein level ratio in blood (OBA_2053927, an Ontology of Biological Attributes entry). Also known as: the ratio of amount of adenine phosphoribosyltransferase (human) in blood to amount of proteasome activator complex subunit 1 (human) in blood.