MS4A1

Membrane spanning 4-domains A1 (MS4A1), more commonly known as CD20, is a B-cell surface glycosylated phosphoprotein that is actively expressed B cells starting at the pro-B phase. It is also known as B1, S7, Bp35, CVID5, MS4A2, or LEU-16. CD20 is proposed to function as a cell membrane calcium channel and also as B cell micro-environmental interaction modulator, which generates optimal B-cell immune response, specifically against T-independent antigens. CD20 also facilitates the development and differentiation of B-cells into plasma cells.

The expression of MS4A1 is regulated through the CXCR4/SDF1 signaling pathway and abnormal expression of MS4A1 is often associated with various cancers including B-cell lymphomas, B-cell chronic lymphocytic leukemia, hairy cell leukemia, and melanoma cancer stem cells. MS4A1 is also associated with Hodgkins disease, myeloma, and thymoma. So far, several monoclonal antibodies against MS4A1 have been developed and applied clinically. ADCs, such as Ibritumomab tiuxetan, are also under active evaluation for the treatments of MS4A1-related B cell lymphomas and leukemias.

Entrez Gene ID: 931
UniProt ID: P11836