Immunohistochemical (IHC) analysis of samples from the Human Protein Atlas (HPA) database further confirmed these trends: KIF21A (Figure 5D) and PIGH (Figure 5E) exhibited low expression, while RPS6KA2 (Figure 5F) exhibited high expression in ccRCC tissues compared to normal tissues. This evidence concerns the gene KIF21A and nonpapillary renal cell carcinoma.