 Investigators will grow these cells from donor in the laboratory in a way that will train them to recognize and remove viruses when the T cells are given after a transplant. Since most donors have previously been infected with EBV, CMV, and adenovirus, investigators are able to use their T cells that remember these viruses to grow the CTLs. However, they now also have a new way of growing CTLs from donors who have not been infected with CMV. 