EGLN2 and cyst: Therefore, to investigate the role of Phds in the regulation of Hif and possibly other relevant pathways affecting cyst formation, we generated mice lacking both Phd1 and −3, (Phd1−/−Phd3−/−) or Phd1, -2, and -3 (Phd1−/−Phd2fl/fl Ksp-Cre+/−Phd3−/− from herein termed Phd1−/−Phd2−/−Phd3−/−).