A compound attribute that is the ratio of amount of low-density lipoprotein receptor (human) in blood to amount of proprotein convertase subtilisin/kexin type 9 (human) in blood. The trait is Ontology of Biological Attributes entry OBA_2054916 (LDLR/PCSK9 protein level ratio in blood). Also known as: the ratio of amount of low-density lipoprotein receptor (human) in blood to amount of proprotein convertase subtilisin/kexin type 9 (human) in blood.