Because decreased abundance of AQP2 in the kidney is sufficient to produce the urinary concentrating defect (Khositseth et al., 2017), the inability to adequately respond to augmented vasopressin-V2R axis can result in production of large volumes of dilute urine, such as occurs in nephrogenic diabetes insipidus (Mamenko et al., 2016). Here, AQP2 is linked to nephrogenic diabetes insipidus.