AQP2 and chronic kidney disease: This rationalise the next step of studies to test the exact roles for the RA/RAR in the CD in different AKI and CKD models, e.g. by selectively up- and down-regulating RA/RAR activity and its downstream genes in the CD cell lineage using Hoxb7 or AQP2 promoters and then examining whether this changes the outcomes of AKI and CKD models in mice9.