GMFB (glia maturation factor beta) is a multifunctional protein that regulates cellular differentiation, actin cytoskeleton dynamics, and metabolic processes. GMFB exhibits tissue-specific distribution with high levels in the central nervous system, thymus, and colon, and shows age-related expression changes 1. The protein functions as an actin filament debranching factor and negatively regulates Arp2/3 complex-mediated actin nucleation, playing crucial roles in cytoskeletal remodeling 2. In pathological conditions, GMFB demonstrates significant disease relevance. In diabetic retinopathy, elevated GMFB impairs chaperone-mediated autophagy by translocating ATP6V1A from lysosomes, leading to ACSL4 accumulation and ferroptosis in retinal pigment epithelial cells 3. GMFB signals through the FAS receptor to activate the FAF1-mediated degradation pathway 4. In metabolic disorders, GMFB deficiency improves insulin resistance by promoting CARM1-mediated lipid turnover in adipocytes 5. The protein undergoes SUMOylation at multiple lysine residues, which regulates its stability and subcellular localization 6. GMFB also contributes to postmenopausal osteoporosis by promoting adipogenesis over osteogenesis in bone marrow mesenchymal stem cells 2. Clinically, GMFB represents a promising therapeutic target, with inhibitors like DS19 showing insulin-sensitizing effects and potential applications in treating diabetic retinopathy and metabolic diseases.