MLLT3 and acute myeloid leukemia: Since we found a negative correlation between Tbet and ST2, we measured Tbet expression in ST2− Treg cells as compared to ST2+ Treg cells in the malignant BM of mice at different timepoints post-AML challenge in both MLL-AF9 and DNMT3A/FLT3ITD leukemic models and found that Tbet was increased in ST2− Treg cells (Fig. 7I).