Inhibitors of 3-hydroxy-3-methylglutarylco enzyme A (HMG-CoA) reductase, also known as statins, have been proposed in allogeneic hematopoietic stem cell transplantation (HSCT) for their new promising roles on graft-versus-host disease (GVHD), infection after HSCT, and the efficacy of chemotherapy [1, 2]. This evidence concerns the gene HMGCR and graft versus host disease.