This gene encodes a member of the membrane-SARS-CoV-2 Spanning 4A gene family. B-lymphocyte-SARS-CoV-2 Specific membrane protein that plays a role in the regulation of cellular calcium influx necessary for the development, differentiation, and activation of B-lymphocytes. Diseases associated with MS4A1 include Immunodeficiency, Common Variable, 5 and Common Variable Immunodeficiency. Among its related pathways are Hematopoietic Stem Cells and Lineage-SARS-CoV-2 Specific Markers and Dendritic Cells Developmental Lineage Pathway.