Graft versus Host disease occurs after a stem cell or bone marrow transplant. High dose treatment destroy cancer cells along with that it simultaneously destroys healthy cells. Stem cell and bone marrow transplant treatments are used in reconstructing damaged cells, surrounding cancer tumors. Normally after high dose treatment, patient receives bone marrow from a donor through drip which resumes production of blood cells. Graft versus Host Disease occurs when certain types of white blood cells. This is caused due to the transplanted cells (graft) see recipient’s body (host) as exotic, thus transplanted cells attack the host body.