Among them, Presage ST2 is theonly US Food and Drug Administration (FDA)-approved assay for clinical use thatcan accurately measure low circulating sST2 levels in healthy individuals; aclinical cut-off of 35 ng/mL is used based on the HF: A Controlled TrialInvestigating Outcomes of Exercise Training (HF-ACTION) study [15, 16]. Here, IL1RL1 is linked to hydrops fetalis.