CD8A and autosomal dominant polycystic kidney disease: This increase in CD8+ T cells is counterbalanced by a decrease in double-negative T cells, whose functional role has not been studied in PKD, but we and others have reported that their numbers increase in ADPKD compared with control in Pkd1RC/RC kidneys as well as ADPKD patient kidneys (Supplemental Figure 3D) (51, 59).