In this study, our biochemical analyses of the metabolism of WT Blimp-1 and the unstable Blimp-1 mutants detected in ABC-DLBCL cell lines and primary ABC-DLBCL samples indicate that the instability of ABC-DLBCL-associated Blimp-1 mutants is largely due to their N-terminal misfolding mutations. Here, PRDM1 is linked to diffuse large B-cell lymphoma.