FGF1 and diabetes mellitus: However, long-term use of wild-type FGF1 (FGF1WT) may increase tumorigenic risks because of its strong mitogenic activity, which limits the applications of FGF1WT in vivo, especially in cancer-prone diseases including diabetes.7 It has been reported that FGF1 is involved in maintaining the metabolic homeostasis of adipose tissue under variations of nutrient availability.14 However, the roles of FGF1 or FGF1 variants in cardiac metabolic homeostasis have not been studied.