A compound attribute that is the ratio of amount of charged multivesicular body protein 1a (human) in blood to amount of proepiregulin (human) in blood. The trait is CHMP1A/EREG protein level ratio in blood (Ontology of Biological Attributes id OBA_2055572). Also known as: the ratio of amount of charged multivesicular body protein 1a (human) in blood to amount of proepiregulin (human) in blood.