PPARGC1A and type 2 diabetes mellitus: In addition, PPARGC1A was positively correlated with BCAA gene expression (ESM Fig. 2a) and BCAA metabolites in individuals with NGT but not type 2 diabetes (ESM Fig. 2b,c), while the expression of several BCAA genes was inversely associated with blood glucose and HbA1c (Fig. 3d).