By contrast, expression of other well-known EMT-inducing transcription factors such as Twist1, Snail1/2, and ZEB1/2 is usually associated with poor prognosis and metastasis in various cancer types [6], which is inconsistent with the concept that the reversal of EMT through reduction of EMT-inducing transcription factors is necessary for efficient metastatic colonization. This evidence concerns the gene ZEB1 and cancer.