BIRC5 and head and neck squamous cell carcinoma: As shown in Figs. 8A and 8B, the relative mRNA expression levels of CDKN2A, BIRC5, and PLAU were higher in HNSCC tissues than in paracancerous normal tissues, while the relative mRNA expression levels of CDKN2A, BIRC5, and PLAU were also higher in both HNSCC cell lines than in HOK cells.