Canine Renal proximal tubular epithelial cells (RPTEpiC) play a crucial role in renal function. They reabsorb almost all the glucose and amino acids in the glomerular filtrate; while allowing the elimination of other substances without nutritional value through the urine. They are also a major site of injury in a variety of congenital, metabolic, and inflammatory diseases. RPTEpiC can produce inflammatory mediators such as cytokines or chemokines and actively participate in acute inflammatory processes by affecting and directing leukocyte chemotaxis via the production of IL-8. RPTEpiC express IL-2R alpha and MHC class II antigens during inflammation after renal transplantation or in crescentic glomerulonephritis; indicating the capacity to participate in the pathogenesis of immune renal injury. To be able to study the relationship between proximal tubular cells and a variety of renal diseases, the RPTEpiC culture provides a useful in vitro model.