Membrane-spanning 4-domains subfamily A member 4A (MS4A4A)

Membrane-spanning 4-domains subfamily A member 4A (MS4A4A) is a tetraspanning transmembrane protein of the MS4A gene family, predominantly expressed in myeloid immune cells, especially macrophages and mast cells. MS4A4A facilitates receptor trafficking, regulates the formation of signaling complexes in lipid rafts (including dectin-1 and FcεRI), and is upregulated during macrophage differentiation, particularly into the M2 anti-inflammatory phenotype. Its expression is induced by glucocorticoid hormones and is seen in tissue macrophages in settings such as COVID-19 and rheumatoid arthritis. MS4A4A is under investigation as a prognostic marker in cancers due to its association with immune cell infiltration in tumors and may serve as a biomarker for immune modulation and tissue homeostasis. No approved drugs directly target this protein[1][2][3].

Other names

MS4A4ACD20L14SPAN1CD20 antigen-like 1Four-span transmembrane protein 1HDCME31PMS4A4MS4A7Fc epsilon receptor beta subunit homolog (some aliases may overlap with closely related MS4A family members but are commonly used for MS4A4A)

Not applicable (no direct-drug mechanism established; protein itself modulates receptor trafficking and signaling, which could be targeted indirectly)