A compound attribute that is the ratio of amount of DNA repair nuclease/redox regulator APEX1 (human) in blood to amount of PC4 and SFRS1-interacting protein (human) in blood. The trait is APEX1/PSIP1 protein level ratio in blood (OBA_2055172). Also known as: the ratio of amount of DNA repair nuclease/redox regulator APEX1 (human) in blood to amount of PC4 and SFRS1-interacting protein (human) in blood.