A compound attribute that is the ratio of amount of syntaxin-8 (human) in blood to amount of ubiquitin carboxyl-terminal hydrolase 8 (human) in blood. The trait is STX8/USP8 protein level ratio in blood (Ontology of Biological Attributes id OBA_2053100). Also known as: the ratio of amount of syntaxin-8 (human) in blood to amount of ubiquitin carboxyl-terminal hydrolase 8 (human) in blood.