This gene encodes a member of the membrane-spanning 4A gene family. Members of this nascent protein family are characterized by common structural features and similar intron/exon splice boundaries and display unique expression patterns among hematopoietic cells and nonlymphoid tissues. This gene encodes a B-lymphocyte surface molecule which plays a role in the development and differentiation of B-cells into plasma cells. This family member is localized to 11q12, among a cluster of family members. Alternative splicing of this gene results in two transcript variants which encode the same protein.,MS4A1,B1,Bp35,CD20,CVID5,LEU-16,MS4A2,S7,Cancer,Tumor immunology,Tumor-associated antigens,Immunology & Inflammation,CD markers,Stem Cells,Hematopoietic Progenitors,MS4A1