SNAI1 and hepatocellular carcinoma: To explore the possible mechanisms by which let-7a represses sphere number, we hypothesized that increased let-7a in HCC cells and HCC stem cells inhibited malignant cellular behaviors through down-regulating N-cadherin and Snail, that has been typical pathological markers for epithelial trait was up-regulated; meanwhile, was involved in the process of epithelial-mesenchymal transition (EMT) (Fig. 4b, Left).