The discovered mechanism of Twist1-mediated upregulation of AGR2 seems especially important as it is AGR2 that is required for Twist1-induced activation of breast tumor cell migration and invasion, which are associated with cancer stemness [268]; thus, the AGR2-Twist1 axis should be considered as one of the endogenous drivers in cancer stemness development. This evidence concerns the gene TWIST1 and breast neoplasm.