Although there has yet to be a clinical trial that specifically regulates IL-10 in HF patients, treatment with growth hormone or intravenous immunoglobulin has been shown to be associated with a marked increase in plasma IL-10 level and consequently improved cardiac contractile performance in HF patients (Gullestad et al., 2001; Adamopoulos, 2003). The gene discussed is GH1; the disease is hydrops fetalis.