The absence of SF-1 (Supplemental Fig. 2A), chromogranin A/synaptophysin, AE1/AE3 cytokeratin, S-100, CD34, and HMB-45 (Supplemental Fig. 2B-G) ruled out pheochromocytoma, metastatic carcinoma, malignant peripheral nerve sheath tumor, angiosarcoma, and malignant melanoma, respectively. The gene discussed is CD34; the disease is metastatic carcinoma.