 As mentioned above, GVHD is a form of transplant rejection. GVHD can affect the digestive system, skin, liver and other body systems. GVHD can increase the risk of infection. After a matched, related donor stem cell transplant, GVHD when severe, is a major cause of discomfort, organ damage, and even death. When a graft vs host reaction develops, but is kept under control, studies show there may be a beneficial graft versus tumor effect, helping to destroy tumor cells in the patient, and thus providing a more effective control of their cancer. 