Pioglitazone slows down cyst growth in a rat model of PKD. Print
EurekAlert: Using a rat model that has the same genetic mutation as a form of human PKD, the two research groups independently tested a pioglitazone treatment regimen and found that it slowed down both kidney and liver cyst growth by inhibiting a chloride channel in the cells of these organs.

... http://www.eurekalert.org/pub_releases/2010-11/iuso-cdd111110.php