The reasons for the controversial results about the correlation between14-bp polymorphism and GVHD are as follows: firstly, HLA-G molecules have ethnical differences; secondly, the incidence of HLA-G 14-bp polymorphisms in the general population is different; thirdly, the HLA system is complex; fourthly, the screening conditions of each research center are different; and last but not least, a large cohort of patients should be performed to further confirm the present results. The gene discussed is HLA-G; the disease is graft versus host disease.