A compound attribute that is the ratio of amount of collagen alpha-3(VI) chain (human) in blood to amount of spondin-2 (human) in blood. The trait is OBA_2053806 (COL6A3/SPON2 protein level ratio in blood). Also known as: the ratio of amount of collagen alpha-3(VI) chain (human) in blood to amount of spondin-2 (human) in blood.