Ontology of Biological Attributes entry OBA_2053139 (RGMB/TNFRSF21 protein level ratio in blood) can be described as follows. A compound attribute that is the ratio of amount of repulsive guidance molecule B (human) in blood to amount of tumor necrosis factor receptor superfamily member 21 (human) in blood. Also known as: the ratio of amount of repulsive guidance molecule B (human) in blood to amount of tumor necrosis factor receptor superfamily member 21 (human) in blood.