IFT20 and cyst: In a similar experiment as that described above, mouse models with tissue-specific and inducible knockouts of Pkd1 and Pkd2 alone or in combination with knockouts of cilia proteins Kif3a and Ift20 revealed that: disruption of cilia reduced cyst growth caused by loss of PC1 or PC2; simultaneous loss of PCs and either Kif3a or Ift20 resulted in milder disease severity than that seen when either PC protein was inactivated; and the length of time that intact cilia existed after the loss of PC’s increased disease severity (42).