Regarding this issue, we proposed and evaluated four different approaches, with the help of the model, to inhibit VEGF synthesis in tumor: (1) direct antagonizing of let-7, (2) overexpression of AGO1 mRNA, (3) overexpression of AGO1 and Dicer mRNA, (4) overexpression of miR-15a by miR mimics. The gene discussed is AGO1; the disease is neoplasm.