Concomitant with the upregulation of SPACA6 levels, elevated expression of the miR-99b∼125a∼let-7e cluster was reported in liver cancer and esophageal squamous cell carcinomas, where it promoted tumor invasion and metastasis through regulation of ZEB1 activity (11, 12, 42). Here, ZEB1 is linked to esophageal squamous cell carcinoma.