STAT5B and leukemia: Consistent with the decreased sensitivity of Lmo2Tg;STAT5-CATg and Lmo2Tg;N1-ICDTg thymocytes to Dynamin inhibition (Supplementary Fig. 2a, b), the anti-leukemic activity of Dynole 34-2 as a single agent was limited in overt leukemia, where LSCs have acquired collaborative mutations of multiple signalling pathways (Supplementary Figs. 5a and 6b).