New data from a next-generation-sequencing study of 15 patients with acute myelogenous leukaemia (AML) has revealed that a subset of patients with clearance of the founding AML clone after induction chemotherapy also develop expansion of a genetically unrelated population of clones. Non-leukaemic, haematopoietic cells harbouring the mutations observed in these newly-expanded populations were detectable at very low levels prior to induction therapy, suggesting that the presence of certain mutations in haematopoietic cells confers a selective survival advantage, and increased proliferation after induction chemotherapy.