A compound attribute that is the ratio of amount of probable carboxypeptidase X1 (human) in blood to amount of proheparin-binding EGF-like growth factor (human) in blood. The trait is CPXM1/HBEGF protein level ratio in blood (Ontology of Biological Attributes term OBA_2054598). Also known as: the ratio of amount of probable carboxypeptidase X1 (human) in blood to amount of proheparin-binding EGF-like growth factor (human) in blood.