TCF4 and breast cancer: The proto-oncogene β-catenin has been linked to the pathogenesis of hepatocellular carcinoma, colorectal carcinoma, lung cancer, malignant breast tumors, and leukemia through the Wnt-signal transduction pathway [16] Immunoglobulin Transcription Factor-2 (ITF-2) is one of several specific target genes of T-cell factor-dependent transcription upon translocation of β-catenin to the nucleus [17].