PTK2 and head and neck squamous cell carcinoma: Interestingly, a decreased expression of zyxin has been reported in laryngeal squamous cell carcinoma (Wu et al., 2011), while an increase of FAK expression has also been reported in the head and neck squamous cell carcinomas (Agochiya et al., 1999), supporting a possible correlation between FAK and zyxin expression levels.