There were significantly more metastases, higher total fluorescence intensity, and MMP2 protein expression in ESCC xenografts in the lenti-CST1 group than in the lenti-NC group, without significant differences in the size, volume and weight of the tumor tissues, elucidating the effect of CST1 on promoting the metastasis of ESCC cells in vivo (Fig. 9A–D). This evidence concerns the gene CST1 and esophageal squamous cell carcinoma.