Furthermore, in vivo, intraperitoneal administration of BRL37344 triggered antidiuresis in AVPR2 conditional knockout mice [8], which are unable to concentrate urine in response to AVP, recapitulating the main hallmark of the rare human genetic disease X-linked nephrogenic diabetes insipidus (XNDI) [1]. The gene discussed is AVPR2; the disease is nephrogenic diabetes insipidus.