CRTAM/KLRD1 protein level ratio in blood (Ontology of Biological Attributes identifier OBA_2054509) can be described as follows. A compound attribute that is the ratio of amount of cytotoxic and regulatory T-cell molecule (human) in blood to amount of natural killer cells antigen CD94 (human) in blood. Also known as: the ratio of amount of cytotoxic and regulatory T-cell molecule (human) in blood to amount of natural killer cells antigen CD94 (human) in blood.