A compound attribute that is the ratio of amount of macrophage scavenger receptor types I and II (human) in blood to amount of tumor necrosis factor receptor superfamily member 21 (human) in blood. The trait is OBA_2054554 (MSR1/TNFRSF21 protein level ratio in blood). Also known as: the ratio of amount of macrophage scavenger receptor types I and II (human) in blood to amount of tumor necrosis factor receptor superfamily member 21 (human) in blood.