As results of tumor cell inoculation, marked decreases of spleen and submandibular lymph node weights, serum IFN-γ, splenic TNF-α, IL-1β and IL-10 contents, splenocytes and peritoneal NK cell activities were observed with histopathological atrophic changes of spleen and submandibular lymph nodes. The gene discussed is IL10; the disease is neoplasm.