JunB is a basic region, leucine zipper (bZIP) transcription factor belonging to the Jun family that includes c-Jun and JunD. Jun family members homodimerize or heterodimerize with Fos and ATF proteins to form a functional transcription factor AP-1 (activator protein, whose activity is regulated by a variety of physiological and pathological stimuli such as growth factors, infections, and stress signals.
