We found that from the spleen tissue, compared with the Saline group, the mRNA level of CD86 in the CON group was significantly decreased, and the mRNA level of Arg-1 in the CON group was significantly increased, suggesting that the ratio of M1/M2 macrophages in the spleen of lung cancer mice are decreased, forming an immunosuppressive microenvironment. This evidence concerns the gene ARG1 and lung cancer.