TCF-4 mainly localizes in the cytoplasm and is transported into the nucleus directly bound to beta-catenin in a cooperative manner. This TCF-4/beta-catenin complex induces expression of Wnt target genes, including multiple cancer-associated genes. c-Jun also interacts with TCF-4 and beta-catenin, and the phosphorylation-dependent interaction between c-Jun and TCF4 regulates intestinal tumorigenesis by integrating JNK and APC/beta-catenin. TCF-4 is also implicated in bipolar affective disorder.
