GCG and type 2 diabetes mellitus: These included the (i) IAPP and (ii) the histone acetyl transferase in the TGF β signaling pathway coding NCOA3 genes, the expressions of both were down-regulated in T2D donor islets, and correlated positively with GCG whereas negatively with INS (iii), HMGA1 (variants associated with T2D), and (iv) BCL2L1 which promotes survival of differentiating pancreatic cells (Loo et al, 2020), both of which showed higher expression in T2D donor islets and correlated negatively with GCG whereas positively with INS (Tables S1 and S5).