This cluster of papers focuses on the use of engineered bacteria, particularly Salmonella typhimurium, for targeted cancer therapy. The research involves various strategies such as tumor-specific colonization, gene delivery, immunotherapy, and metabolic manipulation to induce tumor regression and enhance anti-tumor immunity. Fluorescent protein imaging is utilized to visualize tumor growth, metastasis, and angiogenesis in live animals. Additionally, the cluster explores the use of bacterial vectors for gene therapy and the potential of arginine deprivation as a targeted therapy for certain cancers.