There are currently over 100,000 individuals in the United States in critical care who are in need of organ donation. Unfortunately, many will die before they are able to match with a potential donor. Roughly 17 people die daily while waiting for an organ to become available. These hopeless circumstances are what make xenotransplantation, organ donation by non-human species, so appealing to desperate patients and families. Xenotransplants have some benefits to human donation–animals can be genetically engineered from birth so that their organs will produce less of an immune response once implanted in the human host. Recently, three patients received kidney transplants from genetically modified pigs. In all cases the kidneys succeeded at producing urine. All three patients died within two months, though doctors are unsure as to the cause of death. It seems that xenotransplantation is the future of the organ transplant world, but even if the immune reaction barrier is overcome, are pig kidneys similar enough microscopically to human kidneys to be functional long term? Using qPCR techniques on fresh pig kidney specimens from a slaughterhouse, we set out to answer this question by comparing the tight junction composition of the nephron in both human and pig kidneys. Tight junctions are essential to nephron function, as they control the paracellular permeability of endothelial cells. Extreme alterations to the composition of the nephron tight junctions in pigs, would mean that pig kidneys filter urine differently than humans and could cause major setbacks in the future of xenotransplantation.