Bcl-6, a transcriptional repressor, binds Stat recognition-like DNA elements and influences germinal center development and Th1/Th2 differentiation. Bcl-6 negatively regulates NFkB expression, thereby inhibiting NFkB-mediated cellular functions. HDAC- and silent information regulator (SIR)-2-dependent acet-ylation of Bcl-6 causes downregulation of activity by inhibiting the ability of Bcl-6 to recruit complexes containing histone deacetylases (HDACs). Bcl-6 is frequently deregulated in non-Hodgkin's B cell lymphomas. The human BCL6 gene has been shown to encode a protein of 706 amino acids.