CHEK2 and diffuse large B-cell lymphoma: Concerning the genomic instability of DLBCL, targeted sequencing of 73 key DNA repair genes discovered somatic alterations in several novel and/or potentially functional important mutation targets in DLBCL, including CHEK2, PARP1, and DDB1, and several nonhomologous end‐joining (NHEJ) genes (DLRE1C, PRKDC, XRCC5, and XRCC6), as well as mismatch repair (MMR) genes (EXO1, MSH2, and MSH6) 34.