Attenuated S. typhimurium (S.T.ΔppGpp) was used to engineer a new strain of bioluminescent bacteria that enhanced PDT, promoted the conversion of anti‐inflammatory macrophages (M2) to proinflammatory macrophages (M1), stimulated tumor NK cells, CD4+ Th cells and CD8+ T cells, reduce immunosuppressive Treg cells in TME, and upregulate the expression of various effector cytokines.367. This evidence concerns the gene CD4 and neoplasm.