TCF4 and breast cancer: In general, in the cytoplasm, DDX5/DDX17 promotes the dissociation of β-catenin from the complex and transports it to the nucleus to participate in the transcription of target genes, such as c-Jun, c-Myc, cyclin D1, TCF4, and AKT, then to promote the malignant progression of drug-resistant NSCLC, breast cancer, colon cancer, colorectal cancer, etc. (Figure 4).