SNAI1 and esophageal squamous cell carcinoma: Additionally, knockdown of snail1 reversed the increased expression of MMP14 induced by CTHRC1 (Fig. 6f), indicating that cyclin D1 and snail1 were downstream effectors of FRA-1; in turn, snail1 induced high expression of MMP14 in CTHRC1-overexpressing ESCC cells (Fig. 6g).