It has been demonstrated that Wnt/β-catenin signaling plays an important role in the maintenance of radioresistant aldehyde dehydrogenase positive (ALDH+) prostate cancer cells [32], and that silencing of the Wnt transcription factor TCF4 sensitizes colorectal cancer cells to (chemo-) radiotherapy [33]. This evidence concerns the gene TCF4 and colorectal cancer.