In a viable mouse model of X-linked nephrogenic diabetes insipidus (XNDI) by deleting the V2 vasopressin receptor (V2R), mice administered with selective EP4 receptor agonist ONO-AE1-329 shows greatly improvements in the manifestations of XNDI, with significant reductions in urine volume and water intake while urine osmolality is massively increased (68). The gene discussed is AVPR2; the disease is nephrogenic diabetes insipidus.