MKI67 and nonpapillary renal cell carcinoma: Although it was not feasible to evaluate systematically and quantitatively the cancer invasive edge in the ccRCC samples available for this study, qualitative IHC analysis of single-antigen immunolabelling showed Ki-67 (Figure 3G) to be mainly expressed in the tumor core where MICAL2 (Figure 3H) was not or scarcely expressed, and vice versa (Figure 3I, 3J).