Neurofibromin is the product of the NF1 (neurofibromatosis type 1) gene. NF1 is characterised by café au lait spots, neurofibromas and Lisch nodules. A minority of cases show scoliosis, pseudoarthrosis, short stature, intellectual handicap, macrocephaly and malignancies. Neurofibromin is expressed mainly by Schwann cell, neurons and oligodendrocytes and to a lesser extent in lung, liver, kidney, spleen and colon. Neurofibromin stimulates the GTPase of p21-ras, suppressing cell division and stimulating differentiation.

Immunohistochemical expression

Diagnostic utility



1Sakamoto, A., Oda, Y., Oshiro, Y., Tamiya, S., Iwamoto, Y., Tsuneyoshi, M. Immunoexpression of neurofibromin, S-100 protein, and leu-7 and mutation analysis of the NF1 gene at codon 1423 in osteofibrous dysplasia. Human Pathol 2001;32:1245-1251.


This page last revised 6.5.2002.

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