PTK2 and esophageal squamous cell carcinoma: Moreover, high expression of integrin α6 and p-FAK were significantly associated with poor outcomes in ESCC (Fig. 7C, D), and patients classified as TM4SF1low/integrin α6low/p-FAKlow showed better disease outcome than the TM4SF1high/integrin α6high/p-FAKhigh group (Fig. 7E).