GRK4 and hypertensive disorder: G protein–coupled receptor kinases (GRKs) comprise a family of 7 serine/threonine protein kinases that specifically phosphorylate and regulate agonist‐activated G protein–coupled receptors (GPCRs).4 Specifically, GRK type 4 (GRK4) appears to play a vital role in the long‐term control of BP and in sodium homoeostasis.5 Studies have shown that renal GRK4 modulates dopaminergic‐mediated natriuresis.6, 7 Increased GRK4 activity contributes to the impairment of renal D1R function in hypertension.