In our present study, we observed the highest levels of variation in CD34+ hematopoietic cells, CD123+ plasmacytoid and CD11c+ myeloid dendritic cells, CD19+ B cells, and CD4+CD25+ T cells; all these cell populations can be assumed to play a role in GVHD, GVL, or relapse. This evidence concerns the gene CD19 and graft versus host disease.