A compound attribute that is the ratio of amount of GRB2-related adapter protein 2 (human) in blood to amount of synaptosomal-associated protein 23 (human) in blood. The trait is GRAP2/SNAP23 protein level ratio in blood (Ontology of Biological Attributes id OBA_2053445). Also known as: the ratio of amount of GRB2-related adapter protein 2 (human) in blood to amount of synaptosomal-associated protein 23 (human) in blood.