The invention relates to a composition, comprising a cell population that can be obtained from bone marrow or from blood, when the cell population is depleted of cells that express TCR alpha/beta and cells that express CD19. Such a pharmaceutical composition makes the reconstitution of the immune defense of a person as part of a bone marrow transplantation possible. By means of the invention, the time until the immune reconstitution is considerably shortened and the immune response after treatment are considerably reduced, in particular the occurrence of GvHD. The survival rate of the patient is considerably increased.