HSPCs were transduced with a mix of nine LVs, each of which inserted one of the following oncogenes: Evi1, Glis2, HoxB5, HoxA9, Hlf, Meis1, MyCN, Prdm5, and Runx1. These nine oncogenes were selected on the basis of combined data from previous studies that identified them as leukemia-driving oncogenes together with experimental data previously obtained by our group that identified these oncogenes among HSC transcriptional factors24–29. Here, MEIS1 is linked to leukemia.