Leukemic BM CD8 T cells taken 14 days post leukemic cells challenge are labeled with CFSEhigh mixed with CFSElow non-TME CD8 T cells as target and adoptively transferred with sorted leukemic BM ST2+ Treg cells or WT naïve ST2− Treg cells at a ratio of 1:1 into mice carrying leukemia. The gene discussed is CD8A; the disease is leukemia.