B-aggressive lymphoma family proteins have unique domains that modulate transcription and exhibit poly(ADP-ribose) polymerase activity.

BAL1 (B-aggressive lymphoma 1) was originally identified as a risk-related gene in diffuse large B-cell lymphoma. BAL1 encodes a nuclear protein with N-terminal macro domains and a putative C-terminal poly(ADP-ribose) polymerase (PARP) active site. Macro domains are sequences homologous to the non-histone region of histone macroH2A.