A compound attribute that is the ratio of amount of matrix metalloproteinase-9 (human) in blood to amount of oxidized low-density lipoprotein receptor 1 (human) in blood. The trait is MMP9/OLR1 protein level ratio in blood (Ontology of Biological Attributes entry OBA_2054577). Also known as: the ratio of amount of matrix metalloproteinase-9 (human) in blood to amount of oxidized low-density lipoprotein receptor 1 (human) in blood.