The MS4A gene family in humans includes CD20 (MS4A1), FcRbeta (MS4A2), Htm4 (MS4A3), and at least 13 other genes encoding membrane proteins, most having characteristic tetraspanning topology and similar intron/exon splice boundaries. All family members display unique expression patterns among hematopoietic cells and non-lymphoid tissues. The function of MS4A6A has been suggested to be involved in signal transduction as a component of a multimeric receptor complex in Alzheimer's disease and cancer.Synonyms: 4SPAN3, CD20 antigen-like 3, CD20L3, CDA01, Four-span transmembrane protein 3, MS4A6, Membrane-spanning 4-domains subfamily A member 6A