GIMAP4 is a GTPase family member expressed primarily in immune cells that regulates immune cell function and differentiation. Structurally, GIMAP4 localizes to cytoskeletal elements and the trans-Golgi network, exhibiting higher affinity for GDP than GTP 1. During T helper cell differentiation, GIMAP4 regulates interferon-γ secretion and cytokine production through effects on endoplasmic reticulum-localized chaperones 1. GIMAP4 also appears important during thymocyte development, potentially regulating apoptosis processes 2. Genetically, GIMAP4 variants associate with Behçet's disease susceptibility, a systemic vasculitis, suggesting roles in immune and inflammatory regulation 3 4. GIMAP4 expression is characteristic of ectopic endometrium in endometriosis, linking it to altered immune cell infiltration in this condition 5. In lung adenocarcinoma, reduced GIMAP4 expression correlates with poor overall survival and impaired immune cell infiltration into the tumor microenvironment, compromising immunotherapy efficacy 6. GIMAP4 also associates with bone metastasis development in breast cancer 7. These findings establish GIMAP4 as a key immune regulator influencing both physiological immune responses and pathological immune infiltration across multiple disease contexts.