Core Viewpoint - The research presents a novel endosymbiotic system combining ATP-expressing engineered bacteria and macrophages for cancer immunotherapy, demonstrating significant potential in inhibiting breast cancer progression and metastasis [2][4][6]. Group 1: Research Highlights - The study successfully established an endosymbiotic system through the encapsulation of bacteria with cationic lipid membranes to avoid degradation by macrophage lysosomes [3][5]. - This engineered endosymbiotic system is designed to continuously express ATP, providing essential energy for the metabolic activities of host macrophages and mediating immune activation through lipopolysaccharides [3][5]. - The system enhances the functionality of host macrophages significantly, showcasing its potential in cancer treatment [5][8]. Group 2: Functional Characteristics - The endosymbiotic system exhibits remarkable pro-inflammatory polarization and functional enhancement in the tumor microenvironment, effectively suppressing breast cancer progression and metastasis [4][6][8]. - It is noteworthy that the system can maintain functionality for up to 60 hours even under nutrient-deprived conditions, indicating its robustness [3]. Group 3: Broader Implications - This innovative approach based on the relationship between engineered bacteria and macrophages offers a promising new avenue for cancer immunotherapy and has broad potential applications in various biological contexts [8].