Interestingly, through double immunofluorescence staining of NEK2 and CD8 on ccRCC tissue slices, we found mean fluorescence intensity (MFI) of CD8 (green) significantly increased with the growth of tumor stage, along with the increasing MFI of NEK2 (red) (Fig. 3F). The gene discussed is CD8A; the disease is nonpapillary renal cell carcinoma.