However, in HF, a condition characterized by increased sympathetic nervous system activation (SNS), GRK2 activity/expression is upregulated, and this elevation in GRK2 activity has many adverse effects in the cardiovascular system because it induces massive βAR downregulation, with consequent left ventricular (LV) dysfunction (Cannavo et al., 2018b). Here, GRK2 is linked to hydrops fetalis.