To investigate the role of ATR in maintaining the DZ transcriptional program, we treated two DZ-like lymphoma cell lines, HT and SUDHL-5 (Supplemental Figure 6A), with the ATR inhibitor (ATRi) ceralasertib (AZD6738) or DMSO control for 48 hours (Figure 5A and Supplemental Table 10). This evidence concerns the gene ATR and lymphoma.