GBP-2 belongs to the guanylate-binding protein (GBP) family. GBPs are characterized by their ability to specifically bind guanine nucleotides (GMP, GDP, and GTP). As GTPases induced by IFN-gamma (Interferon-inducible GTPase), they are key to the protective immunity against microbial and viral pathogens. GBP-2 is a GTPase that converts GTP to GDP and GMP. It binds GTP, GDP and GMP. GBP-2 hydrolyzes GTP very efficiently. GDP rather than GMP is the major reaction product. GBP-2 is induced by interferons that have antiviral effects and inhibit tumor cell proliferation.