Akin to the glucose-lowering effects of FGF19, all of these glucose-lowering effects of FGF1 were abrogated by an intra-arterial corticosterone infusion to match plasma corticosterone concentrations to those of the untreated T1D rats and were independent of any alterations in liver (Fig. 6f) or muscle (5.8±0.2 versus 5.9±0.3 versus 5.9±0.1 mg g−1) glycogen content or hepatic gluconeogenic protein expression (Fig. 6g, Supplementary Fig. 2). This evidence concerns the gene FGF1 and type 1 diabetes mellitus.