Moreover, PTTG1 promotes the invasion of esophageal squamous cell cancer cells by inducing epithelial–mesenchymal transformation, and PTTG1 is involved in inducing epithelial–mesenchymal transformation by activating the expression of GLI1 in esophageal squamous cell carcinoma (27). Here, PTTG1 is linked to esophageal squamous cell carcinoma.