The protein encoded by this gene is a zinc finger transcription factor and contains an N-terminal POZ domain. This protein acts as a sequence-specific repressor of transcription, and has been shown to modulate the transcription of START-dependent IL-4 responses of B cells. This protein can interact with a variety of POZ-containing proteins that function as transcription corepressors. This gene is found to be frequently translocated and hypermutated in diffuse large-cell lymphoma (DLCL), and may be involved in the pathogenesis of DLCL. Alternatively spliced transcript variants encoding different protein isoforms have been found for this gene.Synonyms: B-cell lymphoma 6 protein, BCL-5, BCL5, BCL6, LAZ-3, LAZ3, ZBTB27, ZNF51, Zinc finger and BTB domain-containing protein 27, Zinc finger protein 51