 In this study, researchers will collect alloreactive NK cells from the blood of a relative of yours whose HLA proteins do not match yours exactly. The NK cells are separated from the blood using a machine called a CLINIMACs system. This machine uses special kinds of cells and magnetic beads to separate the NK cells. The drug interleukin-2 is then added to the NK cells, to improve their function. The interleukin-2 will be washed out of the cell sample before it is given to you. The CliniMACS System is a medical device that is used to separate types of blood cells from blood that is removed from the body during leukapheresis. These separated cells are processed for use in treatments such as stem cell transplants. 