CD117

Formalin-fixed, paraffin embedded tissue block or cell block, or 1 unstained charged slide for each test requested plus 3-4 additional unstained slides cut at 4 microns. Adequate space on each slide for control tissue is required.

CD117 is a transmembrane receptor to tyrosine kinase. It is a marker of gastrointestinal stromal tumors (GISTs) and the mutated form is the target of Imatinib therapy. The wild type form is expressed in many tissue and cell types including mast cells, germ cells, melanocytes and interstitial cells of Cajal of the intestine.