B2M and diffuse large B-cell lymphoma: In our study, GI-DLBCL exhibited high-frequency mutations in B2M, CCND3, HIST1H1C, BIRC6, TET2, KMT2C, LRP1B, CSMD3, FAT4, RHOA, MUC4, and FBN2, revealing consistent mutation frequencies and variants in common with DLBCL in cBioPortal and COSMIC.