TCF7L1 and colorectal carcinoma: Of remarkable significance, the p.1125Val>Ala mutation in the APC gene, previously reported for its association with the FAP syndrome [32], also increased the expression levels of all the genes downstream of APC gene in the Wnt/β-catenin signaling pathway in the CRC patients, including APC, β-catenin, TCF7L1, TCF7L2, LEF1, MMP7, C-myc, C-jun, and CYCLIND1, and GSK-3β for feedback located upstream of the APC gene (Figure 4).