PTK7 and esophageal squamous cell carcinoma: Additionally, PTK7 promotes proliferation, migration, and invasiveness of esophageal squamous cell carcinoma (ESCC) cells by activating fibroblast growth factor receptor 1 (FGFR1) [30,31,32] and contributes to epidermal growth factor receptor (EGFR)/Akt signaling in TNBC cells [33].