Of note, when considering the role of Twist1 in cancer progression, is the observation that although Twist1 appears necessary for metastasis in the mouse breast cancer model, it is probably not sufficient given that 3 of the 4 cell lines express comparable levels of Twist1 protein yet 2 of the 3 cell lines are largely non-metastatic [36]. Here, TWIST1 is linked to breast carcinoma.