Ontology of Biological Attributes id OBA_2055608 (EGFR/MEGF9 protein level ratio in blood) can be described as follows. A compound attribute that is the ratio of amount of epidermal growth factor receptor (human) in blood to amount of multiple epidermal growth factor-like domains protein 9 (human) in blood. Also known as: the ratio of amount of epidermal growth factor receptor (human) in blood to amount of multiple epidermal growth factor-like domains protein 9 (human) in blood.