That the tumor suppressor genes Fxbw7, Pdcd4, and Stk40 were downregulated at the mRNA and protein level in marked-ZD tumor group (Figure 6) and that they were predicted to interact to alter network of target proteins [65, 66, 77] (Figure 7) provide support that miR-223, miR-21, and miR-31 have an important role in ESCC and may be useful prognostic biomarkers and therapeutic targets for ESCC. This evidence concerns the gene PDCD4 and esophageal squamous cell carcinoma.