We focused on the use of NIH3T3 fibroblast and renal epithelial RCTE cells, in large part to allow comparisons and extrapolations of the role of PD-L1 in ciliopathies, such as PKD, but recognize the possibility of differences between our observations in normal cells and diseased or mutant cells, and in in vivo models. The gene discussed is CD274; the disease is ciliopathy.