To test if reduced Gata2 expression would provide a competitive advantage in vivo, we set up an RNA-interference (RNAi) based competition assay (Fig. 4a) utilizing established Cebpap30/p30 leukemia cells, in which both Cebpa (+56–73%) and Gata2 (+45–56%) levels are increased modestly compared to primary CebpaΔ/p30Tet2+/+ blasts11,34. This evidence concerns the gene CEBPA and leukemia.