A compound attribute that is the ratio of amount of semaphorin-7A (human) in blood to amount of tumor necrosis factor receptor superfamily member 13B (human) in blood. The trait is SEMA7A/TNFRSF13B protein level ratio in blood (OBA_2055752, an Ontology of Biological Attributes identifier). Also known as: the ratio of amount of semaphorin-7A (human) in blood to amount of tumor necrosis factor receptor superfamily member 13B (human) in blood.