DLL1/EFEMP1 protein level ratio in blood (OBA_2053628, an Ontology of Biological Attributes id) can be described as follows. A compound attribute that is the ratio of amount of delta-like protein 1 (human) in blood to amount of EGF-containing fibulin-like extracellular matrix protein 1 (human) in blood. Also known as: the ratio of amount of delta-like protein 1 (human) in blood to amount of EGF-containing fibulin-like extracellular matrix protein 1 (human) in blood.