Effect of concomitant treatment with nucleoside transporter inhibitor NBMPR on TGN and adenine concentrations in ALL cells. (Left) Shown are intracellular TGN concentrations in CEM, Nalm-6, and MOLT-4 cells after treatment with MP in the presence or absence of nitrobenzylmercaptopurine ribonucleoside (NBMPR), a nucleoside transport (SLC29A1) inhibitor. (Right) Shown is the intracellular adenine concentration in CEM cells after incubation with adenine, in the presence or absence of NBMPR. Columns represent the averages of 3 independent experiments, each with 3 replicates; error bars represent range.