Since previous studies have reported that DNA methylation of certain genes such as LY6E [37], S100A4 [38], ITGB2 [39], LGALS1 [40, 41], and IL2RG [42] can downregulate gene expression, we speculate that the application of demethylating drugs may help regulate the expression of related immune genes, improve T lymphocyte dysfunction, and increase the immunogenicity of tumor cells, thereby enhancing the efficacy of subsequent CAR-T cell therapy. The gene discussed is S100A4; the disease is neoplasm.