COL6A3/CST3 protein level ratio in blood (Ontology of Biological Attributes identifier OBA_2053873) can be described as follows. A compound attribute that is the ratio of amount of collagen alpha-3(VI) chain (human) in blood to amount of cystatin-C (human) in blood. Also known as: the ratio of amount of collagen alpha-3(VI) chain (human) in blood to amount of cystatin-C (human) in blood.