TNF and cancer: (a) “leaky” system: knock out Braun’s lipoprotein gene, construct engineered strains with outer membrane integrity deficiency to promote the release of cellular contents. (b) “Trojan Horse” tactic: Through engineered hosts, on the one hand induce TNF-α overexpression, on the other hand release TNF-α -targeting immunotoxins. Via TNF-α, both TNF-α receptors and immunotoxins form a sandwich, thereby promoting RIT internalization and killing cancer cells.