A compound attribute that is the ratio of amount of amyloid-beta precursor protein (human) in blood to amount of platelet-derived growth factor subunit A (human) in blood. The trait is APP/PDGFA protein level ratio in blood (OBA_2053917, an Ontology of Biological Attributes id). Also known as: the ratio of amount of amyloid-beta precursor protein (human) in blood to amount of platelet-derived growth factor subunit A (human) in blood.