S100 beta (EP32)

S100 calcium binding protein B (S100 beta) is a member of the multifunctional S100 family of proteins.1-3 S100 beta acts as a stimulator of proliferation and migration and as an inhibitor of apoptosis and differentiation in many cell types including astrocytes, Schwann cells, chondrocytes, adipocytes, certain neuronal populations, melanocytes, Langerhans cells, histiocytes, epithelial, and myoepithelial cells.1-3 S100 beta is also expressed in neoplasms derived from these cell types, making it a useful marker for the identification of melanoma and various nervous system tumors.1-3 Although ubiquitous, S100 beta has proven to be a sensitive marker for malignant melanoma, including desmoplastic and metastatic variants.1-4