BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in BTB and CNC homolog 2 (BACH2)
BACH2, also called BTB-basic leucine zipper transcription factor 2, belongs to the cap 'n' collar (CNC) and basic leucine zipper (bZIP) factor family. BACH2 is a lymphoid-specific transcription factor with a prominent role in B-cell development. It is transcriptionally regulated by the BCR/ABL oncogene. It represses the anti-apoptotic factor heme oxygenase-1 (HO-1). It is also a potent general repressor of effector differentiation in naive T cells. Moreover, BACH2 is required for pulmonary surfactant homeostasis and alveolar macrophage function. The BTB/POZ domain is a common protein-protein interaction motif of about 100 amino acids.