However, the expression level of Runx3 was decreased in Runx3 siRNA-transfected cells and the inhibitory effect of CpG stimulation on cell proliferation was distinctly reversed by Runx3 siRNA, indicating that CpG-ODN may inhibit the proliferation of TLR9-positive tumor cells by regulating the expression of the tumor suppressor gene Runx3 through the TLR9 signaling pathway. The gene discussed is TLR9; the disease is neoplasm.