Previous studies have provided strong evidence that GRK2 plays a pivotal role in the βAR-mediated development of HF (Iaccarino et al., 1998b; White et al., 2000; Raake et al., 2008) and the increase of GRK2 expression can be used as an early marker for HF (Rengo et al., 2011; Lymperopoulos et al., 2013). This evidence concerns the gene GRK2 and hydrops fetalis.