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 (PubMed:9178770). Binds the second PAH repeat of SIN3A (PubMed:15235594). Ubiquitinated by the CTLH E3 ubiquitin-protein ligase complex, leading to subsequent proteasomal degradation.