FAP/LRRN1 protein level ratio in blood (Ontology of Biological Attributes id OBA_2055356) can be described as follows. A compound attribute that is the ratio of amount of prolyl endopeptidase FAP (human) in blood to amount of leucine-rich repeat neuronal protein 1 (human) in blood. Also known as: the ratio of amount of prolyl endopeptidase FAP (human) in blood to amount of leucine-rich repeat neuronal protein 1 (human) in blood.