GBP1 is an interferon-inducible GTPase that functions as a critical antimicrobial effector in cell-autonomous immunity 1. Its primary function involves hydrolysis of GTP to GMP through two consecutive cleavage reactions, converting GTP to GDP and then to GMP in a processive manner 2. Following pathogen infection, GBP1 localizes to pathogen-containing vacuoles and cytosol-escaped bacteria, where it executes multiple defense mechanisms 34. Mechanistically, GBP1 forms polyvalent protein coats that encapsulate Gram-negative bacteria and directly binds lipopolysaccharide (LPS), disrupting the O-antigen barrier to expose cryptic lipid A that activates the caspase-4 inflammasome 256. This assembly constitutes a massive host-defense nanomachine comprising approximately 30,000 GBP1 molecules with integrated caspase-4 and gasdermin D 7. GBP1 also promotes inflammasome assembly against intracellular pathogens like Legionella and Toxoplasma by liberating pathogenic molecules into the cytosol, where they trigger both apoptosis and pyroptosis 48. Physiologically, GBP1 requires tight regulation; uncontrolled expression induces cytotoxic Golgi fragmentation, prevented by PIM1-mediated phosphorylation and 14-3-3σ sequestration 9. In disease, GBP1 overexpression in immune-hot IDH-mutant astrocytomas correlates with worse prognosis 10. GBP1 confers protection against bacterial pathogens (L.monocytogenes, M.bovis BCG), protozoan parasites (T.gondii), and exhibits antiviral activity 411.