MSTN/RGMA protein level ratio in blood (Ontology of Biological Attributes entry OBA_2054642) can be described as follows. A compound attribute that is the ratio of amount of growth/differentiation factor 8 (human) in blood to amount of repulsive guidance molecule A (human) in blood. Also known as: the ratio of amount of growth/differentiation factor 8 (human) in blood to amount of repulsive guidance molecule A (human) in blood.