A pancreas transplant is an organ transplant that involves implanting a healthy pancreas (one that can produce insulin) into a person who usually has diabetes. Because the pancreas is a vital organ, performing functions necessary in the digestion process, the recipient's native pancreas is left in place, and the donated pancreas is attached in a different location. In the event of rejection of the new pancreas, which would quickly cause life-threatening diabetes, there would be a significant chance the recipient would not survive very well for long without the native pancreas, however dysfunctional, still in place. The healthy pancreas comes from a donor who has just died or it may be a partial pancreas from a living donor. At present, pancreas transplants are usually performed in persons with insulin-dependent diabetes, who can develop severe complications. Patients with the most common, and deadliest, form of pancreatic cancer (pancreatic adenomas, which are usually malignant, with a poor prognosis and high risk for metastasis, as opposed to more treatable pancreatic neuroendocrine tumors or pancreatic insulinomas) are usually not eligible for valuable pancreatic transplantations, since the condition usually has a very high mortality rate and the disease, which is usually highly malignant and detected too late to treat, could and probably would soon return.