Transcriptional repressor that binds to the promoter region of target genes. Plays a role in the regulation of the cell cycle and of the Wnt pathway. Binds preferentially to the sequence 5'-TTCATTCATTCA-3'. Binding to the histone H1.0 promoter is enhanced by interaction with RB1. Disrupts the interaction between DNA and TCF4 (By similarity). Binds TCF4 (By similarity). Binds RB1. Binds the second PAH repeat of SIN3A (By similarity). Highly expressed in liver, adipose tissue, lung, brain, spleen, kidney, skeletal muscle and heart. Not detectable in undifferentiated preadipocytes and myogenic cells. Accumulates at high levels during the terminal stages of the differentiation process. Up-regulated by insulin in differentiated cultured adipocytes. Ubiquitinated by the CTLH E3 ubiquitin-protein ligase complex, leading to subsequent proteasomal degradation.