Studies using breast cancer cell lines have shown an important role of Twist1 in epithelial-to-mesenchymal transformation, intravasation and metastasis (Xu et al., 2017); more importantly, genetically ablating the Twist1 function effectively inhibited breast tumor cell intravasation and lung metastasis (Xu et al., 2017). The gene discussed is TWIST1; the disease is breast cancer.