May have a pivotal role in cell differentiation of different cell types. Signaling could be triggered by the binding of a lectin-like ligand to the CD24 carbohydrates, and transduced by the release of second messengers derived from the GPI-anchor. Modulates B-cell activation responses. In association with SIGLEC10 may be involved in the selective suppression of the immune response to danger-associated molecular patterns (DAMPs) such as HMGB1, HSP70 and HSP90. Plays a role in the control of autoimmunity (By similarity). Expressed in the central nervous system, in postmitotic cells of spinal cord, hindbrain, midbrain and forebrain. Expressed in epithelium during the development of non-neural tissues. Expressed in tooth development, specifically in mesenchymal cells differentiating into odontoblast in dental papilla, as well as in the developing eye and hair follicle. Detected in primitive ectoderm, mesoderm and ventral endoderm; down-regulated when organogenesis is completed. Extensively O-glycosylated (By similarity). The carbohydrate structure may be regulated in a tissue-specific and developmental stage-specific manner. Belongs to the CD24 family.