In our GFP + MLL-AF9 AML mouse models (Fig. 1a–c), we observed that the number of endogenous C/EBPα particles in GFP-tagged MLL-AF9 cells was significantly increased after being treated with Ara-C and Dox (Fig. 1d and Supplementary Fig. 1a), suggesting that the C/EBPα particles may be involved in the cell differentiation induced by chemotherapeutic drugs. Here, KMT2A is linked to acute myeloid leukemia.