CHEK1 and diffuse large B-cell lymphoma: To test whether co‐targeting of the DDR and the SUMOylation pathway could be advanced towards a potential novel therapeutic strategy beyond SLF2 loss, we co‐treated the intrinsically SUMOi‐resistant DLBCL cell line OCI‐Ly1 with a combination of SUMOi (subasumstat) and the CHK1/2 inhibitor AZD7762.