A protocol of activating and administering human blood cells so that bone marrow histology and/or blood cell counts of patients suffering from aplastic anemia approach normal. The protocol includes culturing the blood cells in the presence of a cytokine and an ionophore. It is emphasized that this abstract is provided to comply with the rules requiring an abstract that will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. 37 C.F.R. 1.72(b).