SNAI1 and neoplasm: EMT-TFs, including forkhead box C proteins Foxc1 and Foxc2, Snail, Slug, Sip1, Goosecoid, and the basic helix-loop-helix factors Twist-1 and Twist-2, frequently regulate the expression of one another and, in various combinations, lead to induction of oncoproteins and repression of tumor suppressors to maintain mesenchymal traits [25, 40–42].