A compound attribute that is the ratio of amount of CD99 antigen (human) in blood to amount of tumor necrosis factor receptor superfamily member 19L (human) in blood. The trait is CD99/RELT protein level ratio in blood (Ontology of Biological Attributes entry OBA_2053401). Also known as: the ratio of amount of CD99 antigen (human) in blood to amount of tumor necrosis factor receptor superfamily member 19L (human) in blood.