PKHD1 and Renal cyst: miR-21 is also upregulated in cystic kidneys from Pkd1 conditional knockout mice (Pkd1flox/flox:Pkhd1-Cre mice), Pkd2 conditional knockout mice (Pkd2flox/flox:Pkhd1-Cre mice), and HNF1B conditional knockout mice (Hnf-1βflox/flox:Pkhd1-Cre mice), and in human ADPKD kidneys [36].