With the observed induction of PD-1|PD-L1 in our ADPKD1 model compared with WT and an upregulation of PD-L1 in human ADPKD cells and cystic epithelia, we hypothesized that disruption of the PD-1/PD-L1 interaction would ameliorate cystic kidney disease in our orthologous model. This evidence concerns the gene PDCD1 and cystic kidney disease.