INS and Glucose intolerance: Aggravated glucose intolerance of HFD-fed TfebΔβ-cell mice was accompanied by reduced β-cell function compared to HFD-fed TfebF/F mice as shown by decreased insulinogenic index (Fig. 6b) without significant changes of β-cell mass (Supplementary Fig. 10b), suggesting that Tfeb-KO β-cells could not functionally adapt to increased demand for insulin due to insufficient mitophagy and mitochondrial activity, leading to deteriorated glucose intolerance when metabolic stress was imposed.