CD4 and gastric cancer: (4) Regulation of immune activity: Li et al. isolated a glucan (α-(1→4)-d-glucan with α-(1→6)-linked branches attaching to the O-6 of branch points) that demonstrated an antitumor effect on 1-Methyl-2-nitro-1-nitrosoguanidine-induced gastric cancer mice by promoting spleen lymphocyte proliferation and enhancing natural killer cell activity, raising blood LgA, LgG, and LgM levels and the expression of CD4+ and CD4+/CD8+ [107].