A compound attribute that is the ratio of amount of stromal cell-derived factor 1 (human) in blood to amount of metalloproteinase inhibitor 3 (human) in blood. The trait is CXCL12/TIMP3 protein level ratio in blood (OBA_2055090, an Ontology of Biological Attributes identifier). Also known as: the ratio of amount of stromal cell-derived factor 1 (human) in blood to amount of metalloproteinase inhibitor 3 (human) in blood.