Meanwhile, UCP2 has been shown to be upregulated by glucotoxicity in GLUTag cells, an intestinal L-cell model, and to reduce Glp-1 secretion from GLUTag cells, suggesting that UCP2 contributes to the pathogenesis of T2DM not only in β-cells (Urbano et al., 2016). Here, GLP1R is linked to type 2 diabetes mellitus.