Our kidneys excrete metabolic wastes and help regulate the volume and composition of body fluids. Their vital function is compromised in more than 13 million people in the United States who suffer from kidney disease. In fact, kidney disease ranks fourth in prevalence among major human diseases in the United States. Kidney function can be impaired by infections, poisoning by substances such as mercury, lesions, tumours, kidney stones, shock or circulatory disease. For instance, one of the most common kidney diseases both in the United States and in the world is glomerulonephritis, which is related to the damage of the kidney’s filtering units. The damage is thought to result from an autoimmune response.