MSRA/P4HB protein level ratio in blood (OBA_2054555) can be described as follows. A compound attribute that is the ratio of amount of mitochondrial peptide methionine sulfoxide reductase (human) in blood to amount of protein disulfide-isomerase (human) in blood. Also known as: the ratio of amount of mitochondrial peptide methionine sulfoxide reductase (human) in blood to amount of protein disulfide-isomerase (human) in blood.