METAP1D/PLXNA4 protein level ratio in blood (Ontology of Biological Attributes term OBA_2054537) can be described as follows. A compound attribute that is the ratio of amount of methionine aminopeptidase 1D, mitochondrial (human) in blood to amount of plexin-A4 (human) in blood. Also known as: the ratio of amount of methionine aminopeptidase 1D, mitochondrial (human) in blood to amount of plexin-A4 (human) in blood.