A compound attribute that is the ratio of amount of neurabin-2 (human) in blood to amount of tudor and KH domain-containing protein (human) in blood. The trait is PPP1R9B/TDRKH protein level ratio in blood (OBA_2053461, an Ontology of Biological Attributes entry). Also known as: the ratio of amount of neurabin-2 (human) in blood to amount of tudor and KH domain-containing protein (human) in blood.