After the administration of MSNM@CY1-4, the proportion of Tregs infiltrated in tumor was significantly decreased (p < 0.01), and the proportion of CD4+ T cells and CD8+ T cells was significantly increased (p < 0.05), which was higher than that of the CY1-4 suspension group, indicating that MSNM@CY1-4 can reach the TDLN and block IDO activity during T-cell priming. The gene discussed is IDO1; the disease is neoplasm.