Function
TCF7L2 is a crucial component of the Wnt signaling pathway, influencing MYC expression by specifically binding to its promoter. In the absence of CTNNB1, TCF7L2 acts as a repressor, while in the presence of CTNNB1, it functions as an activator. TCF7L2 facilitates transcription from promoters containing multiple copies of the Tcf motif (5'-CCTTTGATC-3') when CTNNB1 is present. TLE1, TLE2, TLE3, and TLE4 suppress transactivation driven by TCF7L2/TCF4 and CTNNB1. Expression of dominant-negative TCF7L2 mutants results in G1 cell cycle arrest. TCF7L2 is essential for maintaining the epithelial stem-cell compartment of the small intestine.