GSK3B and type 2 diabetes mellitus: Additionally, compared with WT mice, FGF21 deficiency further decreased the phosphorylation of cardiac AKT (Fig. S20A) and GSK-3β (Fig. S20B) induced by T2DM, associated with the upregulation of TRB3 expression (Fig. S20C) and PTEN activity (Fig. S20D) which are the negative regulators of AKT.