Zeta CD117 Antibody. Zeta’s mouse recombinant monoclonal antibody recognizes CD117 or p145kit, a protein of 145kDa. CD117 is found on a wide variety of tumor cells including follicular and papillary carcinoma of the thyroid, adenocarcinomas from endometrium, lung, ovary, pancreas, and breast as well as malignant melanoma, endodermal sinus tumor, and small cell carcinoma. However, the antibody to CD117 has been particularly useful in differentiating gastrointestinal stromal tumors from Kaposi’s sarcoma, tumors of smooth muscle origin, fibromatosis, and neural tumors of the GI tract. The antibody to CD117 is also useful in recognizing myeloblasts in bone marrow biopsy and clot section.