A compound attribute that is the ratio of amount of nibrin (human) in blood to amount of nicotinamide/nicotinic acid mononucleotide adenylyltransferase 1 (human) in blood. The trait is Ontology of Biological Attributes identifier OBA_2054654 (NBN/NMNAT1 protein level ratio in blood). Also known as: the ratio of amount of nibrin (human) in blood to amount of nicotinamide/nicotinic acid mononucleotide adenylyltransferase 1 (human) in blood.