The inhibition effect of rapamycin was also stronger on tumor xenografts from Eca109-SOX9 cells than that from Eca109-vector cells (Fig. 6F), indicating that rapamycin exerted an enhanced anti-tumor effect on ESCC cells with high SOX9 level....The observation that the PI3K/AKT/mTOR signatures were enriched in clinical ESCC samples with high SOX9 expression further suggests a potential role for the PI3K/AKT/mTOR pathway in SOX9-induced esophageal cancer progression.