Cite this page: CD178. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/cdmarkerscd178.html. Accessed July 12th, 2017.
Definition / general
- Aka CD95 ligand, Fas ligand (FasL)
- Important role in T cell mediated cytotoxicity; induces apoptosis in Fas-expressing target cells
- Cells in immune privileged sites (testis, anterior chamber of eye, placenta) constitutively express FasL, which induces apoptosis in Fas-expressing infiltrating T cells, minimizing inflammatory responses that might damage important physiologic functions at these sites
- May influence interaction of tumor cells with host immune system; theory is that FasL+ tumor cells induce apoptosis in infiltrating Fas+ mononuclear cells
- Fas-FasL binding triggers apoptosis in lymphocytes
- Mutations may be related to some cases of Systemic Lupus Erythematosis (SLE)
- Processed by metalloproteases which cause shedding of extracellular portion into blood (sFas L)
Positive staining - normal
- Activated and cytotoxic T cells, testis, anterior chamber of eye, placenta; also Sertoli cells, neurons, thyroid epithelial cells
Positive staining - tumors
- Reed-Sternberg cells of Hodgkin’s lymphoma (nodular sclerosis and mixed cellularity, Am J Surg Pathol 2001;25:388)


