Provided is a method for preventing or treating a disease, said method being characterized in that a viral vector having, integrated thereinto, a gene encoding a protein having a function to kill, stimulate or depress peripheral nerves or a function to alter another nerve cell function is injected topically to an organ excluding brain and spinal cord, a tumor or an area that has undergone tumor resection to cause the infection of the nerves with the viral vector and consequently cause the expression of the protein having the above-mentioned function in the infected nerves, whereby the function of the nerves infected with the viral vector is controlled by the protein so that the function of the organ, excluding brain and spinal cord, to which the nerves are connected is altered. The method can be utilized for providing a therapeutic medicine and a treatment means in the medical industry. Particularly in cancer therapies, this method can be utilized widely both domestically and abroad in such a way that the viral vector is injected topically to a remaining cancer tissue postoperatively to suppress the recurrence or metastasis of the cancer.