CREB1 and renal cell carcinoma: To analyze an association of HLA-G, HLA-E and CREB staining intensity on the overall survival of RCC patients, the respective non-expressing tumor specimen were compared to the strong positive specimens for HLA-G and CREB, respectively, and weak and moderate/strong specimens for HLA-E followed by the generation of Kaplan–Meier plots (Fig. 5).