The results showed that the proportion of BCSCs and the proportion of CTLA4 T cells in the tumor tissues of the+ hrCHI3L1 + sh-NC group were significantly increased, and the cytotoxicity of CD8+ T cells was reduced compared with that of the Mock + sh-NC group; after the exogenous administration of sh-MAF-1 to down-regulate the expression of MAF in the tumor tissues, the proportion of BCSCs in the hrCHI3L1 + sh-MAF-1 group was significantly increased compared with that of the hrCHI3L1 + sh-MAF-1 group. The gene discussed is CTLA4; the disease is neoplasm.