TCF4 and cardiac hypertrophy: In diabetic rats, 1,25(OH)2D3 attenuated myocardial hypertrophy and interstitial fibrosis, improved cardiac function, and rescued cardiac autophagic activity through VDR activation and downstream β-catenin/TCF4/GSK-3β/mTOR (β-catenin/T-cell factor/glycogen synthase kinase-3β/mammalian target of rapamycin) pathway regulation [42].