A compound attribute that is the ratio of amount of platelet-derived growth factor subunit A (human) in blood to amount of serine protease 27 (human) in blood. The trait is OBA_2054047 (PDGFA/PRSS27 protein level ratio in blood). Also known as: the ratio of amount of platelet-derived growth factor subunit A (human) in blood to amount of serine protease 27 (human) in blood.