TWIST1 and neoplasm: Twist, a transcription factor implicated in epithelial–mesenchymal transition (EMT), is moderately expressed in primary 4T1 tumors and highly expressed in 4T1 lung metastases, and it has been previously shown that Twist is a viable vaccine target.25 Hence, we utilized adenovirus recombinant for Twist (Ad-Twist) for this tumor model.