We investigated the effects of Chk1 and Wee1 inhibition in a large panel of lymphoma cell lines: 35 mature B-cell lymphoma cell lines comprising ten MCL and 25 DLBCL cell lines (seven ABC-DLBCL and 18 GCB-DLBCL), by treating them with specific Chk1 and Wee1 inhibitors, respectively PF-00477736 and MK-1775. This evidence concerns the gene CHEK1 and diffuse large B-cell lymphoma.