YAP1 and cancer: Interestingly, the transcriptional regulators WW domain-containing transcription regulator protein 1/transcriptional coactivator with PDZ-binding motif (WWTR1/TAZ) and Yes-associated protein 1 (YAP1), known to be involved in the self-renewal and metastatic properties of cancer cells [19, 20], were significantly (p < 0.05) down-regulated in SNAI2-siRNA treated cells in comparison with control cells, at the transcriptional level by 61% and 57% respectively, with confirmation at the protein level (Figure 5).