Although each DLBCL cell line exhibited a distinct dose-response pattern for ATM-3507-induced growth arrest, 50% growth inhibition after 48–72 h was achieved with nanomolar to low-micromolar concentrations of the drug, indicating that ATM-3507 can inhibit the growth of cell lines that represent different DLBCL subtypes. Here, ATM is linked to diffuse large B-cell lymphoma.