Transcription factor which may be involved in the control of cell cycle progression by the RB1/E2F1 pathway and in B-cell differentiation. Homodimer. Heterodimer with ARID3B. Interacts with E2F1. Interacts with GTF2I and BTK. Shuttles between nucleus and cytoplasm. Widely expressed, with highest expression in skeletal muscle, thalamus, and colon. By p53/TP53 following DNA damage.