MMP2 and esophageal squamous cell carcinoma: In addition, the number of metastases, total fluorescence intensity, and MMP2 protein expression of ESCC xenografts in the lenti-CST1 + rotenone and lenti-CST1 + PD98059 groups were significantly reduced as compared with those in the lenti-CST1 group (Fig. 9A–D), confirming that CST1 might promote metastasis of ESCC cells via the OXPHOS and MEK/ERK pathways in vivo.