Ontology of Biological Attributes term OBA_2053811 (MAD1L1/PSIP1 protein level ratio in blood) can be described as follows. A compound attribute that is the ratio of amount of mitotic spindle assembly checkpoint protein MAD1 (human) in blood to amount of PC4 and SFRS1-interacting protein (human) in blood. Also known as: the ratio of amount of mitotic spindle assembly checkpoint protein MAD1 (human) in blood to amount of PC4 and SFRS1-interacting protein (human) in blood.