S100 (S100B) - Marker for neurogenic and melanocytic cells

The S100 proteins belong to a large family of proteins that are named using the S100 prefix, for example S100A1, S100A7, S100B, et cetera. Many different cells and types of organs express S100 proteins, but diagnostically S100 antibodies are mainly used to identify cells and forms of cancer that are embryonically derived from the neural crest. These include melanocytes (melanoma), Schwann cells (Schwannomas), as well as in neurofibromas and cancers derived from these corresponding cell types.