Källström J, Niinimäki R, Fredlund J, Vogt H, Korhonen LS, Castor A, Schmiegelow K, Thastrup M, Ek T. Allopurinol increases DNA-thioguanine nucleotides during maintenance therapy in pediatric acute lymphoblastic leukemia. Haematologica 2026; 111(5):1835-1839; https://doi.org/10.3324/haematol.2025.288872.