PKD1 and Renal cyst: 2010). In human cystic kidneys, the isoform composition either resembles the isoform composition present in normal kidneys, or subtly trends toward the isoform changes seen in the Pkd1 cKO mice. This demonstrates that the changes in glycosphingolipid metabolism occurring in human cystic kidneys are accurately reflected in the mouse Pkd1 cKO model.