PTK2 and esophageal squamous cell carcinoma: At a mechanistic level, the findings revealed that FAKpoH58 enables the binding of retinoblastoma protein 1 (RB1, in addition to p53, identified as a novel binding partner of FAK-FERM) to the FERM domain and that this scaffolding function of FAK stimulated DNA synthesis in and the proliferation of ESCC cells.