FGF21 and type 2 diabetes mellitus: FGF-21 has been explored as an antidiabetic hepatokine for the treatment of type 2 diabetes with somewhat promising results.32 FGF-21 has been shown to have tissue-specific effects, but ultimately pharmacological overexpression of FGF-21 recapitulates metabolic starvation, thus promoting fuel utilization and decrease in adiposity.23 Indeed, pharmacological overexpression beyond physiological levels could be a promising research goal to explore for the treatment of PCOS.