Although Interferon-α, Intimab(a BCR/ABL tyrosine kinase inhibitor) and stem cell transplantations are the standard therapeutic options, transplant-related morbidity from graft-versus-host disease and mortality rates of 10% to 20% have greatly reduced the allogeneic hematopoietic cell transplantation in clinics[31], while interferon-α is only effective in some patients to some degree and chemotherapeutic intervention does not result in prolonged overall survival[32,33] and the reason is possibly due to some unknown biology of the CML immune regulation[34]. The gene discussed is BCR; the disease is graft versus host disease.