PTK2 and esophageal squamous cell carcinoma: For example, based on bioinformatics analysis, ITGA2 was predicted to be associated with the prognosis of liver cancer [24]; in intrahepatic cholangiocarcinoma, elevated ITGA2 expression promotes type I collagen-induced clonogenic growth of tumor cells [25]; in esophageal squamous cell carcinoma, ITGA2 promotes cell proliferation and epithelial–mesenchymal transition (EMT) through the FAK/AKT pathway, and its high expression can significantly increase the invasion ability of tumor cells [26].