- Fibroblast growth factor-21 improves pancreatic beta-cell function and survival by activation of extracellular signal-regulated kinase 1/2 and Akt signaling pathways. Wente, W., Efanov, A.M., Brenner, M., Kharitonenkov, A., Köster, A., Sandusky, G.E., Sewing, S., Treinies, I., Zitzer, H., Gromada, J. Diabetes (2006)