CXCR4 and cancer: Figure 1 depicts that DPP4 plays a significant role in cancer biology and that inhibition of DPP4 promotes cancer metastasis via induction of the CXCL12/CXCR4/mTOR/EMT axis [135]. The epithelial cells from diabetic mice have shown activated levels of Wnt, BMP and TGFβ signaling when compared to non-diabetic epithelial cells [135,136,137]. Activation in Wnt, BMP, and TGFβ signaling are known to stimulate EMT processes [135].