GIMAP1 (GTPase, IMAP family member 1) is a GTPase believed to regulate lymphocyte survival and immune cell homeostasis. The protein is widely expressed across lymphoid lineages, including T cells, B cells, NK cells, and macrophages 1, with particularly strong expression in mature B cells 1. GIMAP1 functions through interaction with TMX1 to modulate immune signaling pathways and downstream immune-related genes including CMTM5, IL17F, TRAV34, and XCR1 2. Clinically, GIMAP1 expression correlates with disease prognosis across multiple cancers. In lung adenocarcinoma, GIMAP1 is typically downregulated but exhibits elevated expression following immunotherapy 2. High GIMAP1 expression promotes infiltration of CD8+ T cells, activated memory CD4+ T cells, monocytes, and M1 macrophages while reducing M0 macrophages and resting dendritic cells 2. In pancreatic cancer, GIMAP1 is part of a four-gene prognostic signature associated with chemoresistance 3. GIMAP1 has also been identified as a biomarker in ischemic stroke, where it shows high diagnostic potential linked to immune and inflammatory responses 4, and in lung adenocarcinoma ground-glass nodules where reduced GIMAP1 expression correlates with poor prognosis 5. Additionally, copy number variants in GIMAP1 associate with appendicular lean mass, suggesting roles in skeletal muscle cell survival 6.