To further study the role of USP1 in DLBCL, we used two shRNAs against USP1, which remarkably reduced the mRNA and protein levels of USP1 in RL-4RH (rituximab/chemotherapy resistant DLBCL cells), RL, U2932 and SUDHL4 cells (Fig. 2a–d and Supplementary Fig. S2a). Here, USP1 is linked to diffuse large B-cell lymphoma.