 GRK2 is overexpressed in heart failure, and GRK2 inhibition could be used to treat heart failure in the future.Polymorphisms in the GRK4 gene have been linked to both genetic and acquired hypertension, acting in part through kidney dopamine receptors.GRK4 is the most highly expressed GRK at the mRNA level, in maturing spermatids, but mice lacking GRK4 remain fertile so its role in these cells remains unknown.