Mawar Karsa

To the Editor, Translocation of the mixed lineage leukaemia (MLL/KMT2A) gene is present in approximately 10% of acute leukaemias, including 80% of infant acute lymphoblastic leukaemia (ALL), and is associated with poor survival outcomes.1 These rearrangements define a biologically distinct and clinically high-risk subset of leukaemia, characterised by aggressive disease and inferior responses to conventional therapy.

CONFLICT OF INTEREST STATEMENT M.B. is the Founder, President, and CSO at Aminex Therapeutics where he is an employee and stock owner. P.V. participates in polyamine transporter (ATP13A2 and ATP13A3) drug screening and development efforts for cancer and Parkinson's disease, which involves collaboration with industry. There is no conflict of interest for the remaining authors.

Abstract High-risk neuroblastomas, often associated with MYCN oncogene amplification, are addicted to polyamines, small polycations vital for cellular functioning. We have shown that neuroblastoma cells increase polyamine uptake when exposed to the polyamine biosynthesis inhibitor DFMO, currently in clinical trial, and that this mechanism limits the efficacy of the drug.