A compound attribute that is the ratio of amount of hyaluronidase-1 (human) in blood to amount of sphingomyelin phosphodiesterase (human) in blood. The trait is HYAL1/SMPD1 protein level ratio in blood (OBA_2052970). Also known as: the ratio of amount of hyaluronidase-1 (human) in blood to amount of sphingomyelin phosphodiesterase (human) in blood.