GRK4 and Hypertension: Overwhelming data demonstrate that GRKs (GRK2, GRK3, GRK4, GRK5, GRK6), via different mechanisms, play important roles in the regulation of blood pressure (Table).7, 8, 18, 59, 71, 74, 90, 113, 117 Aberrant GRKs in the cardiovascular system and kidney are involved in the pathogenesis of hypertension.