S 100 is a marker of ?

Ans. is 'd' i.e., All of the above o S 100 is normally present in cells derived from the neural crest (Schwann cells, melanocytes, and glial cells), chondrocytes, adipocytes, myoepithelial cells, macrophages, Langerhans cells, dendritic cells, and keratinocytes. It may be present in some breast epithelial cells. o S 100 proteins have been implicated in a variety of intracellular and extracellular functions. S 100 proteins are involved in regulation of protein phosphorylation, transcription factors, Ca' homeostasis, the dynamics of cytoskeleton constitutents, enzyme activities, cell growth and differentiation, and the inflammatory response. SIO0A7 (psoriasin) and S100A15 have been found to act as cytokines in inflammation, paicularly in autoimmune skin conditions such as psoriasis. o Several members of the S-100 protein family are useful as markers for ceain tumors and epidermal differentiation. It can be found in melanomas, 50% of malignant peripheral nerve sheath tumors, schwannomas, paragangliom stromal cells, histiocytoma and clear cell sarcomas. Fuher, S100 proteins are markers for inflammatory diseases and can mediate inflammation and act as antimicrobials.