The idea that CRC cells bear the loss of TCF7L2 because other TCF/LEF family members substitute for it, was sparked by reports of functional interchangeability among TCF/LEF family members34,35 and observations that TCF/LEF expression patterns in CRC cell lines and colorectal tumors differ from those in normal IECs8,10,36,37. This evidence concerns the gene TCF7L2 and colorectal carcinoma.