title: What are they there for?
mesh_terms: D000818:Animals; D001853:Bone Marrow / Q000276:immunology; D001854:Bone Marrow Cells; D006648:Histocompatibility; D006801:Humans; D007125:Immunogenetics; D007165:Immunosuppression Therapy; D007519:Isoantigens; D007942:Leukemia, Experimental / Q000276:immunology; D008214:Lymphocytes / Q000276:immunology; D051379:Mice; D013950:Thymus Gland / Q000276:immunology; D015022:Yugoslavia
chemical_list: D007519:Isoantigens