TCF7L2 and type 2 diabetes mellitus: In recent years, the role of Wnt/β-catenin pathway in type 2 diabetes mellitus (T2DM) has been increasing appreciated.5, 6 Wnt/β-catenin signaling is a key modulator for β-cell insulin secretion,7β-cell neonatal growth, and regeneration.8 As a major transcription factor of Wnt signaling, T-cell factor 7-like 2 (TCF7L2) was shown to mediate its effects through glucagon-like peptide 1 receptor (GLP-1R) signals in our previous publications.