MS4A7 (membrane spanning 4-domains A7) is a membrane protein that plays critical roles in immune cell function and disease pathogenesis. In dendritic cells, MS4A7 is essential for cross-presentation and antitumor immunity, with expression upregulated after tumor antigen uptake and required for priming antigen-specific CD8+ T cells 1. The protein is prominently expressed in disease-associated macrophages, particularly TREM2+ macrophages in metabolic dysfunction-associated steatohepatitis (MASH), where it exacerbates liver injury through direct interaction with NLRP3 inflammasome 2. MS4A7 also modulates inflammatory responses through lipid droplet efferocytosis, where its downregulation contributes to dampening proinflammatory signaling in macrophages 3. In cancer contexts, MS4A7 is associated with tumor-associated macrophages and M2 polarization. A short isoform (MS4A7-s) promotes glioblastoma progression by activating the PI3K/AKT/GSK3β pathway in glioma-associated macrophages 4. MS4A7 expression correlates with patient prognosis in various cancers and serves as a biomarker for immunotherapy response prediction 5. The protein functions as a component of multimeric receptor complexes involved in signal transduction, particularly in immune cell activation and disease-associated phenotypes.