A compound attribute that is the ratio of amount of cyclin-dependent kinase inhibitor 1 (human) in blood to amount of cyclin-dependent kinase 4 inhibitor D (human) in blood. The trait is Ontology of Biological Attributes term OBA_2054410 (CDKN1A/CDKN2D protein level ratio in blood). Also known as: the ratio of amount of cyclin-dependent kinase inhibitor 1 (human) in blood to amount of cyclin-dependent kinase 4 inhibitor D (human) in blood.