In our current study, we demonstrated that (1) Cy3G, which is widely distributed in edible fruits and vegetables, inhibits EMT and breast cancer cell migration and invasion, (2) the effects of Cy3G on EMT and breast cancer cell migration and invasion are mediated by KLF4, and (3) mechanically, Cy3G inhibits the expression of the KLF4 E3 ligase, FBXO32, leading to stabilization of KLF4 and suppression of EMT and cell migration and invasion. The gene discussed is KLF4; the disease is breast cancer.