Radioligand-binding studies with 125I-cyano-pindolol and selective antagonists showed that β1-specific downregulation of β-ARs also occurred in our immunisation-induced HF-model [18], and that this downregulation was largely prevented by (mono-)application of β1EC2-CP alone (Fig. 4A and B). This evidence concerns the gene CTBP1 and hydrops fetalis.