A compound attribute that is the ratio of amount of amyloid-beta precursor protein (human) in blood to amount of C-C motif chemokine 28 (human) in blood. The trait is APP/CCL28 protein level ratio in blood (Ontology of Biological Attributes id OBA_2055178). Also known as: the ratio of amount of amyloid-beta precursor protein (human) in blood to amount of C-C motif chemokine 28 (human) in blood.