To evaluate whether the immune checkpoint pathway is upregulated in human ADPKD tissue, we performed Western blotting for PD-L1 in immortalized PKD1+/+ cells (renal cortical tubular epithelial [RCTE] cells, WT) and PKD1–/– cells (9-12 cells, ADPKD). This evidence concerns the gene PKD1 and autosomal dominant polycystic kidney disease.