FNDC5 and type 2 diabetes mellitus: In accordance with these results from our group, Liu et al. [57] demonstrated that irisin significantly increased the proliferation of rat insulin secreting INS-1 cells via the ERK and p38 MAPK signaling pathways, protected the cells from high glucose-induced apoptosis by regulating the expression of pro- (Bax, Bad and caspases) and antiapoptotic (Bcl-2 and Bcl-xl) proteins, and improved pancreatic β-cell function in a T2D model in male rats.