Metastatic ccRCC involving the thyroid typically demonstrates positive immunoreactivity for RCC marker, CD10, PAX-2, PAX-8, vimentin and carbonyc anhydrase IX (CA IX) and negative staining for thyroglobulin (TG) and thyroid transcription factor-1 (TTF-1) (18–21). The gene discussed is MME; the disease is renal cell carcinoma.