AQP2 and Renal cyst: Specifically, we demonstrate that physiologically relevant stimulation of TRPV4 expression and activity in cystic cells by high KCl diet increases basal [Ca2+]i levels, partially restores mechanosensitivity, and causes intracellular AQP2 retention (reduced cAMP levels) to markedly slow the development and growth of renal cysts in PCK453 rats (Figure 8, right panel).