A compound attribute that is the ratio of amount of plexin-A4 (human) in blood to amount of ubiquitin carboxyl-terminal hydrolase 8 (human) in blood. The trait is PLXNA4/USP8 protein level ratio in blood (Ontology of Biological Attributes entry OBA_2053526). Also known as: the ratio of amount of plexin-A4 (human) in blood to amount of ubiquitin carboxyl-terminal hydrolase 8 (human) in blood.