GBP2 (guanylate binding protein 2) is an interferon-inducible GTPase that functions as a key mediator of innate immunity and inflammatory responses 1. The protein hydrolyzes GTP to GDP as its major reaction product and plays crucial roles in host defense against bacterial, viral, and protozoan pathogens 1. GBP2 promotes inflammasome activation by directly binding and aggregating lipopolysaccharide (LPS), creating protein-LPS interfaces that enhance caspase-4 activation independently of bacterial surface binding 2. Beyond antimicrobial functions, GBP2 acts as an inhibitor of viral infectivity by suppressing furin-mediated maturation of viral envelope proteins 1. The protein also promotes M1 macrophage polarization through activation of the Notch1 signaling pathway 3. In pathological contexts, GBP2 contributes to ferroptosis in endothelial cells during sepsis-induced acute lung injury by promoting GPX4 ubiquitination through interaction with OTUD5 4. Clinically, GBP2 expression correlates with better prognosis in microsatellite stable colorectal cancer and enhanced response to anti-PD-1 immunotherapy 5. The protein represents a promising therapeutic target, with applications ranging from sepsis treatment to endometriosis therapy 64.