However, the studies have described partly contradictory results regarding the influence of the three most frequent genotypes (HLA-E*01:01/01:01, HLA-E*01:01/01:03, HLA-E*01:03/01:03) on transplant-related mortality (TRM), acute, and chronic GvHD, relapse, disease free survival (DFS), and overall survival (OS) after HSCT (12–22). The gene discussed is HLA-E; the disease is graft versus host disease.