Effect of radical operation on expression of interleukin-2(IL-2)mRNA and production of IL-2 were markedly reduced preoperatively and four weeks after operation,expression of IL-2 mRNA significantly enhanced,but it was still lower than that in the normal group.Production of IL-2 nearly reached normal level,When PBL was activated by phytohemagglutinin(PHA),expresseion of IL-2 mRNA and production of IL-2 were much higher than that in non-activated PBL.These results suggested that expression of IL-2 were much higher than that in non-activated PBL.These results suggested that expression of IL-2 mRNA and production of IL-2 are dificient in gastric cancer patients,and radical surgery will help them to recover and they can also be improved through activation with PHA.