CD55/CHI3L1 protein level ratio in blood (OBA_2054234) can be described as follows. A compound attribute that is the ratio of amount of complement decay-accelerating factor (human) in blood to amount of chitinase-3-like protein 1 (human) in blood. Also known as: the ratio of amount of complement decay-accelerating factor (human) in blood to amount of chitinase-3-like protein 1 (human) in blood.