Nerve growth factor receptor (p75NGFR), is the first of neurotrophin receptors to be isolated and is a member of the tumor necrosis factor (TNF) receptor family. NGFR has been shown to be a reliable marker for desmoplastic and neurotropic melanoma by several groups. It is now apparent that expression of NGFR is ubiquitous and not limited to the nervous system, being expressed in mature nonneural cells such as perivascular cells, follicular dendritic cells, basal epithelium of oral mucosa and hair follicles, prostate basal cells and myoepithelial cells. Studies in prostate and urothelial cancer suggest that NGFR may act as a tumor suppressor, negatively regulating cell growth and proliferation. Anti-NGFR labels the myoepithelial cells of breast ducts and intralobular fibroblasts of breast ducts and thus aides in the diagnosis of malignancy in the breast.