HIF1A and nonpapillary renal cell carcinoma: To determine whether the RNA data can be extended to protein expression levels in ccRCC, we performed immunohistochemistry (IHC) analysis using anti-SENP1, HIF1α, and HIF2α antibodies with a custom tissue microarray (TMA) containing 190 benign and 471 malignant ccRCC tumor samples (Fig. 1C).