Background：CD24 is a 35-45 kD glycosylphosphatidylinositol （GPI）-linked protein also known as heat stable antigen （HSA）, BA-1, Ly-52, and nectadrin. It is expressed on the surface of B cells （but not plasma cells）, granulocytes, follicular dendritic cells, and epithelial cells. CD24 may play a role in the regulation of B-cell proliferation and maturation. CD24 crosslinking induces a Ca2+ flux in mature B cells. CD24 has been shown to interact with CD62P （P-selectin）.
