YAP1 and head and neck squamous cell carcinoma: In light of emerging evidence that YAP is essential in cancer cell invasion and metastasis including HNSCC [3, 5, 8], we evaluated the role of YAP in the metastatic potential of OSCC lines by using transient RNA interference (RNAi, with two hits) to knockdown YAP in buccal carcinoma lines H157 and H413 that had high and moderate levels of YAP expression, respectively (Fig. 1A,B).