Background：CD24 is a 35-45 kD protein also known as Heat Stable Antigen （HSA）, Ly-52, or Nectadrin. It is a GPI-linked sialoglycoprotein expressed on lymphocytes, granulocytes, epithelial cells, thymocytes, monocytes, erythrocytes, and dendritic cells. CD24 expression varies during T and B cell differentiation and is a useful marker for delineating various lymphocyte developmental stages. CD24 serves as an adhesion or costimulatory molecule involved in T and B lymphocyte activation and differentiation by homophilic binding or binding to CD62P.
