AVPR2 and autosomal dominant polycystic kidney disease: ADPKD is typically associated with elevated AVP, which is implicated in cyst growth and disease progression.6 Desmopressin, a synthetic analog of AVP, increases cyclic AMP levels in kidney epithelial cells through V2R signaling, a major driver of cyst growth by promoting cell proliferation and fluid secretion, which increases TKV.7 In contrast, AVP-D is characterized by reduced AVP levels, which would be expected to slow cyst growth and potentially delay disease progression.2