MANF/PPIB protein level ratio in blood (OBA_2053820, an Ontology of Biological Attributes id) can be described as follows. A compound attribute that is the ratio of amount of mesencephalic astrocyte-derived neurotrophic factor (human) in blood to amount of peptidyl-prolyl cis-trans isomerase B (human) in blood. Also known as: the ratio of amount of mesencephalic astrocyte-derived neurotrophic factor (human) in blood to amount of peptidyl-prolyl cis-trans isomerase B (human) in blood.