Islets are usually infused into the person's liver. If the cells are not from a genetically identical donor the person's body will recognize them as foreign and the immune system will begin to attack them as with any transplant rejection. To prevent this immunosuppressant drugs are used. A study from 2005 showed that islet transplantation has progressed to the point that 58% of the people were insulin independent one year after the operation. A review published 2016 reported a 50 – 70 % rate of insulin independence after five years, in five studies from leading transplant centers published 2005 – 2012.