Integration of an Evi1-GFP reporter allele in the inducible iKMT2A-MLLT3 mouse line allowed us to demonstrate that a single dose of the cytokine TPO significantly and specifically increased the fraction of cycling Evi1high HSC and accelerated disease induction of iKMT2A-MLLT3 AML. The gene discussed is TPO; the disease is acute myeloid leukemia.