DDX11 and oncocytic adenoma: Immunohistochemistry analysis of cryopreserved tissue sections prepared from normal kidney, benign renal tumors (angiomyolipoma and oncocytoma), localized low-grade ccRCC, localized high-grade ccRCC, and advanced high-grade ccRCC using an antibody against human DDX11 revealed strong expression of DDX11 in advanced and high-grade ccRCC, whereas weak DDX11 expression was noted in localized and low-grade ccRCC (Figure 1A).