Functions as a transcriptional repressor (PubMed:17014843). May inhibit the activity of CTNNB1 in a TP53-dependent manner and thus regulate cell growth (PubMed:17873903). May function in adipocyte differentiation, negatively regulating mitotic clonal expansion (By similarity). Plays a role in cell-cell adhesion and epithelium development through its interaction with proteins of the beta-catenin family (By similarity). ; (Microbial infection) Plays a role in hepatitis delta virus (HDV) genomic replication.